Update Dec. 20 11p.m. (all times local) 

The Associated Press reported that at 10:25 p.m. local time, State Department spokesman John Kirby said there is not enough information for U.S. officials to validate  the claim of responsibility for the attack made by the Islamic State group hours earlier at 8:35 p.m. local time. Rep. Adam Schiff,  top Democrat, of the House Permanent Select Committee on Intelligence, said  the claim "cannot be verified until the perpetrator or perpetrators are apprehended by German authorities, but ISIS has never shied away from claiming credit for attacks - even if it knew nothing about them in advance."

Update Dec. 20 9:15 p.m.

London police have set a new plan for road closures surrounding Buckingham Palace during the Changing the Guard military ceremony as a "a precautionary measure," The AP reported. There is currently a "severe" threat level in Britain.

Update Dec. 20 7:35 p.m.

The U.N. Security Council condemned the attack and "expressed their deep sympathy and condolences to the families of the victims, as well as to the government of Germany," The Associated Press reported.

Update Dec. 20 7:05 p.m.

German authorities have released a man arrested for crashing a truck into a Christmas market in Berlin after prosecutors found insufficient evidence linking him to the incident, the Associated Press reported.

Original story

Berlin police have raised the death toll to 12, and as many as 48 were injured when a truck drove into a crowded Christmas market in Berlin Monday, the Associated Press reported.

German Chancellor Angela Merkel said that it was a terrorist attack, The New York Times reported.

"There is still a lot that we don't know about this act with sufficient certainty, but we must, as things stand, assume it was a terrorist attack." Merkel said. "I know that it would be particularly difficult for all of us to bear if it would be confirmed that this deed was carried out by a person who sought protection and asylum in Germany."

German police said a passenger in the truck died at the scene and a man originally believed to be the driver was arrested near the scene.

The AP is reporting that Germany's top security official said that the man detained came from Pakistan and had applied for asylum. The man denied involvement in the crash.

Conflicting reports say it's unclear if police arrested the correct man, The AP reported.

Berlin's police chief said it isn't confirmed that the man they've detained was the driver.

De Welt, a German newspaper, is reporting that police said they have the wrong man and that the man who drove through the market is still at large.

Holger Muench, the head of Germany's Federal Criminal Police Office, said he cannot rule out that suspects involved in the truck attack could still be at large.

Witnesses said they believed the incident was deliberate, noting that the truck was traveling at least 40 miles per hour as it headed into the market.

"It looks like something that was adapted by Nice," Julian Reichelt, editor-in-chief at Bild, a German tabloid newspaper, told CNN in reference to the Bastille Day truck attack in Nice, France. At least 80 people were killed during the July 14 attack, and more than 400 people were injured.