BERLIN — Germany on Wednesday launched a Europe-wide manhunt for a "violent and armed" Tunisian man with ties to Islamic extremists who has used at least six different names and three different nationalities, saying he is a suspect in the Berlin Christmas market attack.

A German security official said that authorities had considered him a possible terror threat previously and had been trying to deport him after his asylum application was rejected this summer.

Germany issued a notice to other European countries overnight seeking the arrest of 24-year-old Anis Amri, but initially held off on going public so as not to jeopardize the manhunt. After German media published photos of him and a partial name, federal prosecutors went public with the information.

Federal prosecutors described Amri as of average height and weight, with black hair and brown eyes.

"Caution: He could be violent and armed," the notice warned. "A reward of up to 100,000 euros ($105,000) has been issued for information leading to the suspect's arrest."

A separate European arrest warrant from Germany obtained by The Associated Press states that Amri has at times used at least six different names and three different nationalities.

"This is a suspect, not necessarily the perpetrator," Interior Minister Thomas de Maiziere said after briefing Parliament's domestic affairs committee. "We are still investigating in all directions."

Twelve people were killed and 48 injured when a truck plowed into a popular Berlin market Monday evening in an attack claimed by the Islamic State group. Twelve of the wounded were still being treated Wednesday for very serious injuries and some were in critical condition, Berlin health officials said.

De Maiziere wouldn't give further details on the suspect, but committee members said he had spent time in pre-deportation detention.

Germany's chief federal prosecutor told lawmakers "this Tunisian is a solid lead, his wallet was found in the cab of the truck, but that it's not clear that he was also the perpetrator," said Burkhard Lischka of the Social Democrats, the junior governing party.

Stephan Mayer, a senior lawmaker with Germany's governing conservatives, said the Tunisian was in his early 20s and considered part of the "Salafist-Islamist scene" by authorities.

The suspect apparently arrived in Germany in July 2015 and has lived in three German regions since February, mostly in Berlin, said Ralf Jaeger, the interior minister of western North Rhine-Westphalia state.

Jaeger told reporters that state police had launched proceedings against the man on suspicion that he was preparing a serious crime. He said "security agencies exchanged information about this person in the joint counter-terrorism centre , the last time in November."

Separately, the man's asylum application was rejected in July. German authorities prepared to deport him but weren't able to do so because he didn't have valid identity papers, Jaeger said. In August they started trying to get him a replacement passport.

"Tunisia at first denied that this person was its citizen, and the papers weren't issued for a long time," Jaeger said. "They arrived today."

A Tunisian official said German investigators are trying to determine Amri's role in the Berlin market attack. The official, speaking on condition of anonymity before German officials spoke more about the investigation, said Tunisian authorities were requesting more information on the German probe.

The claim of responsibility carried on the IS group's Amaq news agency did not identify the man seen fleeing from the truck in Berlin, but described him as "a soldier of the Islamic State" who "carried out the attack in response to calls for targeting citizens of the Crusader coalition."

Germany's top prosecutor, Peter Frank, told reporters the attack was reminiscent of a deadly July rampage in the southern French city of Nice and appeared to follow instructions published by IS. He also said it wasn't clear whether there was one perpetrator or several in the Berlin attack.

On July 14, a Tunisian living in France was shot to death after carrying out a truck attack on Bastille Day revelers in Nice, killing 86 people.

Police in Berlin, meanwhile, said they had received over 500 tips on the Monday evening attack.

Shortly after the attack, police arrested a Pakistani man a kilometre (1/2 mile) away who matched witness descriptions of the truck's driver, but he was released the next day for lack