Merkel's premiership is hanging by a thread today as thousands gathered to call for her resignation while a key political ally dramatically withdrew his support over immigration policy.

More than 5,000 protested in Berlin and thousands more throughout Germany over the 'open-door' policy that many have blamed for four brutal terrorist attacks that left 13 dead over the last month.

The Chancellor faced a fresh wave of fury after it emerged that two recent terror attacks and a third killing were carried out by men who entered the country as refugees.

More than 5,000 protested in Berlin and thousands more throughout Germany over the 'open door' policy that many have blamed for four brutal terrorist attacks that left 13 dead over the last month

The Chancellor faced a fresh wave of fury after it emerged that two recent terror attacks and a third killing were carried out by men who entered the country as refugees, which further fuelled the right-wing movement

Despite the massive waves of criticism from right-wingers (pictured, Berlin, today, wearing a shirt that says The German Reich lives within us), Merkel defended her policy this week

Police manned the streets of Germany, which is still on high alert following the attacks, as right-wing protesters met thousands of counter-demonstrators (pictured, Berlin)

The Chancellor (pictured after the Munich shootings) faced a fresh wave of fury after it emerged that two recent terror attacks and a third killing were carried out by men who entered the country as refugees

Despite the massive waves of criticism, Merkel defended her policy this week, dramatically proclaiming 'we can do it' as she pledged not to let the violent acts guide political decisions.

But now her key ally in Bavaria - which bore the brunt of the attacks - has launched a fresh attack on her leadership, distancing his party from Merkel and straining the coalition that keeps her in power.

Horst Seehofer, the conservative premier of Bavaria, said he did not share Merkel's 'we can do it' credo on accommodating the almost 1.1 million migrants and refugees who arrived in 2015.

Seehofer, who leads the Christian Social Union, the sister party to Merkel's conservative Christian Democrats, said today '"We can do this" - I cannot, with the best will, adopt this phrase as my own.'

Horst Seehofer, the conservative premier of Bavaria, said he did not share Merkel's 'We can do it' credo on accommodating 1.1million migrants in 2015

Speaking after a meeting with the Bavarian government in Tegernsee, he added that the solutions to date were 'too inadequate.'

Stressing he had no wish to start a quarrel with Merkel's party, Seehofer said it was important to look 'reality' in the face.

An axe rampage, a shooting spree, a knife attack and a suicide bombing in the span of a week stunned Germany, leaving 13 people dead, including three assailants, and dozens wounded.

Three of the four attackers were asylum seekers, and two of the assaults were claimed by the Islamic State group.

'Merkel must go' has been trending on social media, with people posting powerful pictures including one claiming that she has blood on her hands after recent attacks.

The picture shows her splattered with blood, while another depicts her wearing a Burka.

A new survey found that 83 per cent of Germans see immigration as their nation's biggest challenge - twice as many as a year ago.

Recent attacks have fuelled the right-wing movement, which has long called for stricter immigration controls, particularly in Bavaria, where she faces heavy criticism from high-profile politicians.

Today, thousands of protesters calling for her to step down also met counter-protests from the anti-right-wing movement, in Germany - which is still in a state of high alert.

Thousands gathered in the capital for the march today, which was called Wir fuer Berlin und Wir fuer Deutschland (We for Berlin and We for Germany)

'Merkel must go' (pictured on the placard today) has been trending on social media, with people posting powerful pictures including one claiming that she has blood on her hands after recent attacks

Several hundred people demonstrate with banner that reads 'Berlin! Better without Nazis' against a right-wing populist march in Berlin

One picture shows her splattered with blood (pictured), while another depicts her wearing a Burka

Some believe that the open door policy that has brought more than one million Syrians to Germany is destroying the country. Pictured is an image circulating on Twitter

There was a heavy police presence (pictured) in Washington Square in Berlin as activists protested today

But in a powerful speech on Thursday, Merkel said that she would not allow jihadists to keep her government from being guided by reason and compassion.

'Despite the great unease these events inspire, fear can't be the guide for political decisions,' she said.

'It is my deep conviction that we cannot let our way of life be destroyed,' she added.

After the Bavaria attacks, Seehofer initially called into question the principle that asylum seekers should never be sent back to war zones. He later backtracked, citing international law.

However, he insisted previously: 'We must seriously consider how such people should be treated if they violate the law or can be considered a danger.'

Ali David Sonboly reportedly saw it as an 'especially positive fate' that his birthday was on the same day as Adolf Hitler's, April 20

Flowers and tributes are left at the Olympia Shopping Centre in Munich where Ali David Sonboly killed nine people in a shooting rampage on Friday

Axe attack: The bloody week of violence in Germany began with Pakistani teenager Riaz Khan Ahmadzai, 17, posing as an Afghan refugee slashing passengers on a train in Wurzburg, wounding five

Carnage: Gruesome pictures taken in the hours after the attack showed the blood-soaked interior of the train. Ahmadzai, who appeared in a chilling ISIS video, was shot dead by police

On Saturday he cited the security situation in France, Germany and specifically Bavaria, saying there was an urgent need 'to take action.'

'That's why, here in Germany, we still have some way to go to improve in all areas,' he said.

Jens Spahn, deputy finance minister and a senior member of Merkel's conservatives, said that integrating the refugees was a Herculean task but the government needed to put more pressure on those new arrivals unwilling to make an effort to fit in.

'A ban on the full body veil - that is the niqab and the burka - is overdue,' he told daily Die Welt. 'My impression is that we all underestimated a year ago what would come upon us with this big refugee and migration movement.'

Evil: ISIS jihadi Mohammad Daleel, a failed Syrian asylum seeker, blew himself up outside a wine bar in Ansbach after he was turned away from a music festival for not having a ticket

Video: Daleel, who injured 12 people in the attack, appeared in a chilling video pledging his allegiance to ISIS. His claim for asylum was rejected and he was one of 200,000 in the country awaiting deportation

A spate of sexual assaults on women in Cologne at New Year was blamed on the migrant influx and the country has been left reeling after four brutal attacks in the space of a week.

The deadliest was carried out by a German-born teenager who opened fire at a shopping mall in Munich, killing nine people before turning the gun on himself.

FOUR DEADLY ATTACKS IN A WEEK The deadliest attack came last Friday when a German-Iranian teenager who was born and raised in Munich opened fire at a downtown shopping mall, killing nine people before turning the gun on himself. He had been under psychiatric treatment and investigators say he was obsessed with mass shootings, including Norwegian rightwing fanatic Anders Behring Breivik's 2011 massacre. They have ruled out an Islamist motive, saying the assailant had far-right 'sympathies'. On July 18, an asylum seeker from Afghanistan or Pakistan slashed train passengers and a passer-by with an axe and a knife in Wuerzburg before being shot by police. And on Sunday, a failed Syrian asylum seeker blew himself up outside a music festival in Ansbach, wounding 15 people at a nearby cafe after being turned away from the packed open-air venue. IS claimed both attacks. Already steeped in grief and shock, Germans were further rattled by news that a Syrian refugee had killed a 45-year-old Polish woman with a large kebab knife at a snack bar in the southwestern city of Reutlingen Sunday in what authorities called a personal dispute. Advertisement

Investigators said he had psychiatric problems and far-right 'sympathies' and have ruled out any Islamist motive.

But IS has claimed responsibility for two attacks in Bavaria - a failed Syrian asylum seeker who blew himself up outside a music festival in Ansbach, wounding 15, and an Afghan asylum seeker who slashed five train passengers with an axe and a knife before being shot by police.

A Syrian refugee killed a Polish woman with a knife in Reutlingen, although authorities blamed the attack on a personal dispute.

She announced new security measures including an 'early warning system' to detect radicalisation among refugees, better training for the military to respond to attacks and quicker deportation of failed asylum seekers.

Mohammed Daleel, the Ansbach suicide bomber, was able to stay in Germany despite his asylum application being rejected and twice being ordered to be deported.

Mrs Merkel said the EU's deal with Turkey would mean the number of migrants arriving in Germany would be greatly reduced.

But she repeated her conviction that the country had a duty to help people fleeing war and persecution, adding: 'I am still convinced that we can do it – it is our historic duty and this is a historic challenge.'

The state government in Bavaria has called for an upper limit on numbers of new asylum seekers, and tougher controls on those already in Germany.