Deadly Berlin truck attack: What we know

A truck plowed into a Christmas market in Berlin on Monday night, killing 12 people and wounding nearly 50 others.

Here’s what we know so far:

Islamic State calls Berlin attacker a 'soldier' 

The Islamic State claimed responsibility Tuesday for the Berlin rampage. The militant group called the unknown attacker a "soldier of the Islamic State," the militant group's Amaq News Agency reported.

German Chancellor Angela Merkel said Tuesday the incident was an "assumed terror attack.” The attack is reminiscent of a truck attack in July in Nice, France — the vehicle drove in to a crowd that was celebrating Bastille Day celebrations, killing 86 people. The Tunisian driver was shot and killed by police. The Islamic State claimed responsibility for that attack.

ISIL calls Berlin attacker a 'soldier' as manhunt for killer resumes

New suspect emerges Wednesday

A new suspect emerged  after police found documents in the truck belonging to a 24-year-old Tunisian national identified only as Anis A, German magazine Spiegel reported. A document relating to asylum was found in the cabin, Spiegel and Allgemeine Zeitung reported. The document said Anis A. was born in the southern Tunisian city of Tataouine in 1992, Spiegel said. Interior Minister Thomas de Maiziere confirmed that authorities are seeking a new suspect, but gave no further details. German lawmaker Stephan Mayer said the new suspect is thought to be Tunisian with links to Islamic extremists and was apparently supposed to be deported from Germany earlier in the year.

Prosecutors release other suspects 

German authorities resumed searching for the truck driver who plowed into a crowded Christmas market after prosecutors released a suspect Tuesday, saying there was insufficient evidence tying him to the attack.

Prosecutors said the suspect, a Pakistani who arrived in Germany last year, denied involvement in Monday's attack, and no forensic evidence shows he was in the cab of the truck.

A further suspect was held overnight and released Wednesday due to insufficient evidence, the RBB broadcaster reported, according to German news agency DPA.

Berlin attack puts pressure on Angela Merkel's political survival

Truck owned by Polish firm

Police said the truck, which was loaded with steel beams, was owned by a Polish delivery company, ARIEL Żurawski. The firm said the truck left Poland earlier Monday and the company lost contact with Lukasz Urban, the 37-year-old driver, the cousin of the firm's owner Ariel Zurawski, at around 3 p.m. local time, AFP reported. Zurawski said he believed the truck was hijacked. “I can say, hand on heart, that the man who drove into those people in the center of Berlin was not my driver,” he said, according to the Telegraph.

Some victims identified

Six of those killed were identified as Germans, and a man found shot and killed in the truck’s passenger seat was Polish. The other five people killed have not yet been identified, the Associated Press reported.

Link to refugees?

Germany has been the target of a series of small-scale attacks over the last year. Monday’s attack has stoked further criticism of Chancellor Angela Merkel’s decision to allow nearly 1 million refugees into the country last year.

Merkel earlier said it would be particularly troubling if the attacker turned out to be an asylum seeker. "This would be especially despicable toward the many Germans who are daily engaged in helping refugees, and toward the many people who truly need this protection," she said Tuesday at a news conference.

Nigel Farage, a member of the European Parliament for Britain’s anti-immigration U.K. Independence Party, tweeted, “Terrible news from Berlin but no surprise. Events like these will be the Merkel legacy.” The tweet was condemned by some other Twitter users.

Contributing: Jessica Durando; Kim Hjelmgaard