Widows of Munich victims last night condemned Jeremy Corbyn’s visit to graves of terrorists linked with the massacre.

They demanded an apology for what they described as an ‘act of maliciousness, cruelty and stupidity’.

The Labour leader also came under pressure from Jewish groups and his own MPs over his ‘despicable’ trip to Tunisia.

He has refused to answer key questions about the visit to a cemetery where members of Black September – the terror group that killed 11 Israelis at the 1972 Olympics – are buried.

The Mail’s revelations about the trip in 2014 have deepened the anti-Semitism row engulfing Mr Corbyn. Photographs in Saturday’s newspaper showed him holding a wreath near the graves of those implicated in Black September and the Munich attack. Mr Corbyn was also apparently observing a prayer during a service to honour Palestinian ‘martyrs’.

Widows of Munich victims last night condemned Jeremy Corbyn’s visit to a cemetery where members of Black September – the terror group that killed 11 Israelis at the 1972 Olympics – are buried

Labour has insisted Mr Corbyn was there to commemorate 47 victims of an Israeli airstrike on a Palestine Liberation Organisation base in Tunisia in 1985

Labour has insisted he was there to commemorate 47 victims of an Israeli air strike on a Palestine Liberation Organisation base in Tunisia in 1985.

But he wrote shortly after the trip that wreaths had been laid not just for the 1985 victims but ‘on the graves of others killed by Mossad’. And it emerged yesterday that the air strike memorial at the cemetery is inscribed with the names of some of the terror chiefs.

Ilana Romano, whose husband Yossef, a champion weightlifter, was castrated and shot dead by the Munich terrorists, said Mr Corbyn was ‘a danger’.

The 71-year-old from Tel Aviv added: ‘To go to the grave of a person behind the killing of 11 athletes, he should be ashamed and apologise. He’s not a person of peace. It doesn’t bother him to hurt the families. A person who goes to the grave of killers doesn’t want peace.’

Ankie Spitzer, who lost her husband Andre, a fencing coach, at Munich, said Mr Corbyn was ‘hate-filled’.

She and Mrs Romano together said: ‘We do not recall a visit of Mr Corbyn to the graves of our murdered fathers, sons and husbands. They only went to the Olympics to participate in this festival of love, peace and brotherhood; but they all returned home in coffins.

‘For Mr Corbyn to honour these terrorists, is the ultimate act of maliciousness, cruelty and stupidity.’

Home Secretary Sajid Javid suggested Mr Corbyn should quit, saying the leader of any other major party would have done so by now.

Jonathan Goldstein, chairman of Jewish Leadership Council, said the revelations in the Mail were ‘despicable’.

It emerged yesterday that the airstrike memorial at the cemetery is inscribed with the names of some of the terror chiefs

Mr Corbyn wrote shortly after the trip that wreaths had been laid not just for the 1985 victims but ‘on the graves of others killed by Mossad’

He added: ‘It is reprehensible that the man who wishes to be our prime minister honoured ruthless terrorists who committed an act described by the late King Hussein of Jordan as “a savage crime against humanity”.

‘This man is not fit to be a member of parliament, let alone a national leader.

‘He has spent his entire political career cavorting with conspiracy theorists, terrorists and revolutionaries who seek to undo all the good for which our ancestors have given their lives. In so many ways, enough is enough.’

Labour MP Joan Ryan, chairman of Labour Friends of Israel, said: ‘These pictures appear to show Jeremy Corbyn standing at the grave of the founder of the terrorist group which cold-bloodedly murdered 11 Israeli athletes at Munich.

‘He must now both urgently explain why he chose to honour such a man and unreservedly apologise to the families of the innocent sportsmen who were butchered in the most horrific manner.’

Another Labour MP said: ‘Jeremy’s past is catching up with him. He’s spent the last 40 years supporting or defending all sorts of extremists and in some cases terrorists and anti-Semites.

‘It is shocking to discover that less than a year before he became Labour leader he said himself he was present when wreaths were laid at the graves of the Black September terrorists who murdered athletes at the Olympics.’

Sources close to Mr Corbyn have insisted he was at the service to commemorate only the air strike victims. But their monument is 15 yards from where Mr Corbyn is pictured - and in a different part of the cemetery complex. Instead he was in front of a plaque that lies beside the graves of Black September members. It honours Salah Khalaf, who founded Black September; his key aide Fakhri al-Omari; and also Hayel Abdel-Hamid, PLO chief of security.

Adjacent to their graves is that of Atef Bseiso, a PLO intelligence chief who has been linked to the Munich atrocity.

Atef Bseiso (left) was head of intelligence for the Palestine Liberation Organisation (PLO) before his assassination outside a Paris hotel in 1992. It was widely reported he was shot because he helped plan the Munich Massacre in 1972. Hayel Abdel-Hamidwas chief of security for the PLO. He was a close adviser to Salah Khalaf, and the pair were killed in an attack in Abdel-Hamid’s home in the Tunisian capital Tunis in 1991

Salah Khalaf (left) is widely believed to have masterminded the Munich Massacre. He created Black September and went on to become Yasser Arafat’s second-in-command in the PLO. In 1991 he was gunned down in Tunis. FakhriAlomari was a senior member of Black September and was also implicated in the Munich Massacre. He was a close adviser to Salah Khalaf and was killed during the same attack in Tunis

In an October 2014 article for the communist Morning Star recording his visit to the Tunisian cemetery, Mr Corbyn said wreaths were laid to mark the 1985 bombing but also ‘on the graves of others killed by Mossad agents in Paris in 1991’.

There appears to be no record of Mossad having carried out an assassination in Paris in 1991. However, Khalaf, Abdul-Hamid and al-Omari were assassinated that year. Mossad is accused of killing Bseiso in Paris in 1992.

Labour’s insistence that Mr Corbyn did not honour those involved in the Munich massacre last night is further undermined because the names of Khalaf, Abdul-Hamid and al-Omari are also inscribed on the monument to the air strike. Pictures and videos posted on the Facebook page of the Palestinian embassy in Tunisia over several years show that a wreath is routinely put on the plaque honouring Khalaf, Abdul-Hamid and al-Omari.

Yesterday when the Daily Mail posed a series of questions about the visit to the cemetery, a Labour source said: ‘We have got nothing to say beyond what we have already said.’

The Munich row comes amid controversy over Labour’s refusal to adopt in full an international definition of anti-Semitism, including a list of examples of anti-Semitic behaviour.

Three senior union leaders – from the GMB, Unison and Usdaw – have added their voices to calls from deputy leader Tom Watson for the complete International Holocaust Remembrance Alliance text to be incorporated into Labour’s new code of conduct on anti-Semitism.

A Labour Party spokesman said it had agreed to re-open the development of the code, in consultation with Jewish community organisations and groups.

Writing in the Sunday Mirror, shadow chancellor John McDonnell said: ‘Both Jeremy Corbyn and I have made clear that racism and anti-Semitism have no place in the Labour Party.’

First hooded Palestinian terrorists tortured 11 Israeli Olympic athletes in Munich... then they murdered them in an atrocity that shocked the world, writes MARK ALMOND

The sadism shown by the terrorists of the Munich Olympic Massacre touched the depths of evil. After breaking into the Olympic Village during the Games in 1972, eight Palestinian gunmen rounded up Israeli athletes and their coaches.

During a bloody and unequal battle, one man was killed outright and another — weightlifter Yossef Romano, who was on crutches following a competiton injury — was shot and then castrated.

In a further act of unspeakable savagery, the attackers forced their captives to watch as his body was mutilated.

Whether he was still alive, and exactly what the terrorists thought this would achieve, has never been known. Other athletes were beaten until their bones snapped.

File photo shows a member of the Palestinian terrorist group who seized members of the Israeli Olympic team at their quarters at the Munich Olympic Village on September 5, 1972

The scene of horror inside the apartment of the Israeli Olympic team's apartment which is riddled with bullet holes and blood covering the floor

The full horror was kept from Yossef's widow, Ilana, for 20 years. When eventually she saw photographs of his corpse, it was, she said, 'as bad as I could have imagined. Until that day, I remembered Yossef as a young man with a big smile. But it erased the entire Yossi that I knew'.

That degree of abhorrent cruelty was calculated. The gunmen set out to hijack the Olympics for their own cynical ends, sending out a potent message to their supporters.

It was the first time the Games had been held in Germany since the notorious 1936 Berlin event under Nazi rule. For Israeli athletes to be taking part, less than 30 years after the Holocaust, was deeply symbolic.

West German policemen wearing sweatsuits, bullet-proof vests and armed with submachine guns, take up positions on Olympic Village rooftops

The terrorists' goal, in 18 hours of crazed violence, was to shatter any fledgling spirit of reconciliation.

Indeed, at the climax of the atrocity, nine more Israeli athletes were slaughtered, apparently when they were just moments from freedom, on an airport runway.

This was also the first televised terrorism. Not until the Twin Towers attack of 9/11 would the world be so gripped and so sickened by an act of terror.

The mayhem that played out in Munich was watched by 900 million people in a hundred countries as it happened.

Mixing murder with media spectacle, it set the template to be exploited by Osama Bin Laden's hijackers as they crashed planes into Manhattan and Washington landmarks in 2001.

And yet, in a gesture that defies belief, it was close to the graves of the men who plotted this horror that Jeremy Corbyn, now the Labour Party leader, apparently laid wreaths and joined in an act of prayer at a Tunisian cemetery four years ago.

The remains of the helicopter which was used by Arab guerillas to escape from the Olympic village with 11 Israeli hostages. The helicopter was destroyed in a gun battle with German police

Their plan for the massacre took shape at a pavement cafe on a sunny piazza thronged with tourists in Rome in July 1972. As three Palestinians sat sipping coffee and watching the girls go by, they griped bitterly that, unlike Israel, their state had not been invited to send a team to the Olympic Games that would start in a matter of weeks in the southern Bavarian capital, Munich.

The Palestinian absence should not have been a surprise. No other country recognised the state — not even Communist Russia, which had broken off relations with Israel.

Mohammad Daoud Oudeh (better known by the nom de guerre Abu Daoud), a co-founder of the Black September terror organisation, listened as his two chief lieutenants planned their twisted vengeance.

'Why don't we enter the Olympics in our own way?' asked Fakhri al-Omari, his chief aide.

Salah Khalaf (known as Abu Iyad), a co-founder of Black September and an intelligence chief with the Palestine Liberation Organisation (PLO), asked sceptically what they could do there.

Ilana Romano's husband, brave weightlifter Yossef says he was subjected to torture before being brutally murdered in 1972

'We could seize Israeli athletes,' said al-Omari.

We know this conversation took place because, long after the other two had been assassinated, Mohammad Daoud Oudeh — by then a hard drinker, despite his Muslim faith — boasted to newspapers of the story. (He died of kidney disease in 2010.)

He also revealed how he flew to Munich at the start of the Games and posed as a Brazilian tourist to get a guided tour of the athletes' quarters.

So it was that at 4.30am on September 5, 1972, a group of eight terrorists (it did not include the cowardly ringleaders) scaled an unguarded fence at the Olympic Village. Wearing tracksuits just like athletes would, they used stolen keys to break into the Israeli dormitory block at 31 Connollystrasse.

Daily Mail's coverage of the Munich Massacre a day after the helicopter was shot down, which resulted in five terrorists and all eleven athletes being killed

Tribute: Jeremy Corbyn pictured in 2014 holding a wreath at a cemetery in Tunis. Sources close to Mr Corbyn insisted he was at the service to commemorate 47 Palestinians killed in an Israeli air strike on a Tunisian PLO base in 1985

11 VICTIMS OF MUNICH MASACRE Weightlifter Yossef Romano Weightlifter Ze'ev Friedman Wrestler Mark Slavin Weightlifter David Berger Shooting coach Kehat Shorr Wrestler Eliezer Halfin Coach Moshe Weinberg Fencing coach Andre Spitzer Wrestling judge Yossef Gutfreund Weightlift coach Yakov Springer Athletics coach Amitzur Shapira

Almost at once, they were confronted by wrestling coach Moshe Weinberg and referee Yossef Gutfreund.

Both men were taken prisoner at gunpoint after a fight, in which Weinberg was injured. The kidnappers demanded to be taken to the athletes' rooms. Knowing that his wrestlers would fight back hardest, Weinberg led the terrorists to their quarters in Apartment 3.

He was right. Even unarmed and startled from their sleep, the wrestlers nearly managed to overwhelm their attackers.

Weinberg was at the point of wresting a gun from a terrorist when he was shot and killed. It was then that Yossef Romano was also gunned down — to die horribly in front of his friends.

Nine others were held at the point of AK-47 assault rifles — weapons supplied to Black September by neo-Nazi groups in Germany. Unrepentant Nazis saw the PLO as their allies in a war on Jews. Weinberg's body was dumped outside the front door and Black September's demands were issued. They wanted the release of 234 Palestinian prisoners in Israel, along with the notorious leaders of the Baader-Meinhof terror gang in prison in West Germany.

Ulrike Meinhof was a heroine to the radical Left in Europe because she had organised attacks on U.S. targets, as well as West German officials.

She dismissed victims of the Holocaust with contempt, calling them 'money Jews' or capitalists who deserved to be gassed — but the Left overlooked that.

The Palestinians had not missed the significance of Meinhof's anti-Semitism. They saw her as a comrade-in-arms.

Bargaining with terrorists was out of the question for Israel, which said immediately that there would be no negotiation. But, in the first of a string of monumental blunders, the German government offered a cash ransom.

After a 12-hour standoff, Munich police, most with no training for a hostage rescue, took up positions ready to storm the building: the operation was called off when they realised their actions were being filmed by news crews from all over the world and broadcast live. The terrorists could see everything they did.

The TV broadcast showed the Israeli fencing coach Andre Spitzer, who spoke German, being dragged to a window with an AK-47 muzzle in his back, to demonstrate to the world that some hostages were still alive.

But, even as he attempted to answer a negotiator's question, Spitzer was being clubbed to the ground with the rifle butt. (After seeing the room where he was held hostage, his journalist wife Ankie said: 'I said to myself, 'If this is what happened to that peace-loving man, my husband, who wanted nothing more than to take part in the Olympics, then I will never shut up, never stop talking about the travesty to the Olympic ideals.' ')

The terrorists demanded an airliner on which to make their escape to Cairo, Egypt. With their captives bound and blindfolded, they were taken in buses to two helicopters, which airlifted them to Furstenfeldbruck Air Base 15 miles away.

German police made a ham-fisted attempt at an ambush, using a Boeing 727 on the Tarmac with 17 police disguised as Lufthansa air crew. But, after a panicked 'vote' among themselves, the police abandoned their posts. They later said that, without proper training or weapons, they had no hope of saving the hostages and regarded it as a suicide mission.

When the helicopters landed, bringing the eight terrorists and nine surviving athletes to the airfield, they were surrounded by police — concealed and at a distance.

Later analysis by the SAS revealed this was the perfect opportunity to kill the kidnappers. But the police had no radio contact with each other and, instead of sniper rifles, had been issued with assault weapons that lacked telescopic sights or night vision.

Armoured cars had been despatched, but were stuck in traffic.

After one policeman accidentally opened fire on his own comrades, a gun battle erupted. By the time it was over, five terrorists, a German policeman and all the athletes were dead. Five of the Israelis died when a terrorist threw a hand grenade into one of the helicopters where they were trapped.

Three terrorists were arrested but, in a final blunder, West Germany freed them two months later, in response to another hijack staged by Black September.

Western democracies might delude themselves into negotiating with hostage-takers, but Israel was less obliging. Prime Minister Golda Meir ordered the execution of all the ringleaders by her secret services, in an operation codenamed Wrath Of God.

This, as much as the atrocity in Munich, was the real game-changer in the fight against terrorism: for the first time, a Western government was prepared to use deadly force as a counter-terrorism policy.

One by one, over 20 years, the terrorists behind the massacre were hunted down. It was a murky, ruthless and even pitiless manhunt.

Salah Khalaf (Abu Iyad) was shot in the head by his own bodyguard in Tunisia in 1991, along with his fellow plotter Fakhri al-Omari at the home of Hayel Abdel-Hamid, PLO head of security and a close adviser to Khalaf (although his role in the massacre is not clear).

The Israelis were almost certainly behind the killings — though, of course, their Mossad secret service does not release such details.

The fourth man whose grave Jeremy Corbyn seemed to dignify with his close presence, wreath and prayers was Atef Bseiso, another senior PLO agent known to be directly involved in Munich. He was assassinated as he returned home from dinner in a Paris restaurant in 1992.

One unnamed Mossad source later remarked: 'Our blood was boiling. When there was information implicating someone, we didn't inspect it with a magnifying glass.'

The murderers of 1972 had started a cycle of violence that they would not survive.

Eventually, the PLO came to see terrorism as a dead-end. Hijackings and the killing of innocents such as the Israeli athletes made it impossible for the Palestinians to portray themselves as underdogs. Instead, it highlighted their merciless cruelty.

And, by appearing to 'forget' the horror of what happened in Munich in 1972, Corbyn's actions are troubling, to say the least.