Germany has become victim of what appears to be the latest mass terror attack to rock Europe after a lorry drove through a crowd at a packed Christmas market in Berlin on Monday evening.

The incident killed at least 12 people and injured nearly 50.

Here is all that we know so far about the incident, and what has happened since.

What happened?

The truck was travelling at around 40mph as it crashed into people gathered around wooden huts serving mulled wine and sausages at the foot of the Kaiser Wilhelm memorial church in the heart of West Berlin.

Eyewitnesses described “a big boom” and then “blood and bodies everywhere”.

Australian student Trisha O’Neill, who witnessed the incident, told ABC: “All of a sudden there was a big boom and the people in front me jumped on top of me.

Video shows immediate aftermath of Berlin lorry attack

”All the lights went out and everything was destroyed. I could hear screaming and then we all froze. Then suddenly people started to move and lift all the wreckage off people, trying to help whoever was there.

“There was blood and bodies everywhere.”

Briton Emma Rushton, who was in the market, saw the lorry rush past her at speed and said it could not have been an accident.

She told Sky News she only missed being caught in the chaos because she had climbed up some steps to take a seat.

Ms Rushton said: “The stall that we bought our mulled wine from was completely crushed. People were tearing off wooden panels to get out.

”It was not an accident. It was going 40mph, it was in the middle of the market. There was no way that it could have come off the road and it showed no signs of slowing down.

Suspect detained.. But reports state he is the "wrong man"

On Monday night police detained a Pakistani refugee named “Naved B” in relation with the incident, but it was later reported that it was the "wrong man".

The 23-year-old, who is thought to have arrived in Germany in February before being granted a temporary residence permit in June 2016, denied involvement in the attack, according to German interior minister Karl Ernst Thomas de Maizière.

German newspaper Die Welt later quoted a senior police source as saying: “We have the wrong man. And thus a new situation.

"For the real culprit is still armed at large and can cause new damage."

Hours after the incident Berlin police said they were investigating it as a “suspected terror attack” that deliberately intended to cause harm.

Berlin attack: Suspect arrested by German police

Police wrote on Twitter: “Our investigators assume that the truck was deliberately steered into the crowd at the Christmas market at Breitscheidplatz.

”All police measures concerning the suspected terror attack at Breitscheidplatz are being taken with great speed and the necessary care,“ they added.

Special forces stormed the makeshift migrant camp at the Flughfen Tempelhof airport hangar where the suspect was believed to live in the early hours of Tuesday morning.

Four men were questioned at the centre but no arrests were made, according to a spokesman for the refugee agency.

Possible hijack

Berlin Police spokesman Thomas Neundorf said a passenger in the lorry — who officials later confirmed was a Polish national — was among those killed.

According to the Brandenburg Ministry of the Interior, the Polish passenger of the alleged assassin was probably shot, adding that the man was a victim and not an offender.

The Polish owner of the truck, Ariel Zurawski, said the driver was being driven by his cousin and told TVN24 “they must have done something to my driver”.

Political reaction

German Chancellor Angela Merkel has said “we must assume” the deaths in Berlin “were a terrorist attack”, saying it would be “repugnant” if it was true that a refugee was responsible.

The Chancellor added that she was "shocked and very saddened" by what had happened in the German capital.

British Prime Minister Theresa May sent a message of condolence to Mrs Merkel on Monday evening “to express that her thoughts were with the people of Berlin and we stand ready to assist in any way we can”, a Number Ten spokesperson said.

France's right-wing National Front leader Marine Le Pen meanwhile called for France, the US and, more interestingly, Russia, to form a coalition to fight Islamic fundamentalism, using anti-immigration rhetoric in criticising a weak international approach in battling Islamic extremism.

Eurosceptic German MEP Marcus Pretzell, who has previously called for German border guards to use “armed force” against asylum seekers, blamed Ms Merkel for the incident, tweeting: “When will the German rule of law strike back?”

“When will this cursed hypocrisy end? It is Merkel's dead!”

Ms Merkel has shifted her policy towards refugees and migrants to the right in recent weeks, including a speech in which she suggested stemming the number entering Germany and restricting the use of face veils.

Germany admitted almost 900,000 migrants in 2015 after deciding to allow in those who had made it to Hungary, and although the numbers had dropped sharply in 2016, her Christian Democratic Party (CDU) has suffered internal strife and a string of poor election results.

Former Ukip leader Nigel Farage also took to social media in the wake of the outrage, saying: “Terrible news from Berlin but no surprise. Events like these will be the Merkel legacy.”

The comment prompted hundreds of retweets and replies, including from Brendan Cox, whose Labour MP wife was shot and stabbed to death by neo-Nazi Thomas Mair days before June's EU referendum.

The widower of murdered MP Jo Cox hit out at Nigel Farage on Twitter over the former Ukip leader's responsem saying Mr Farage was heading for a “slippery slope” after the right-wing politician linked the carnage in the German capital with Chancellor Angela Merkel's policies.

Mr Cox wrote: “Blaming politicians for the actions of extremists? That's a slippery slope Nigel.”

Tributes

As emergency services prepared to remove the lorry on Monday night, tributes began to appear nearby, as people laid red candles and flowers, while others wept as they passed the scene.

A glass jar with a white candle inside had a note pinned to it, which read: “I am Berlin for more humanity and sympathy.”

Context of caution

The incident came less than a month after the US State Department called for caution in markets and other public places across Europe, saying extremist groups including Islamic State and al-Qaida were focusing “on the upcoming holiday season and associated events.”

Al-Qaida and Isis have both called on followers to use trucks in particular to attack crowds.

The Berlin attack comes months after Isis claimed responsibility for an attack on 14 July, in which a Tunisian living in France plowed a truck into Bastille Day revelers in the southern French city of Nice, killing 86 people.

Heightened security for the UK

The attack has led to heightened security concerns in the UK, with Scotland Yard saying it will review security arrangements for events over Christmas and New Year following the deadly incidents in Berlin and Ankara.