Berlin attack: Police unsure suspect is lorry attacker

The German authorities say they cannot be sure if a man in custody was behind Monday's lorry attack on a Berlin Christmas market that killed 12 people.

"We have to entertain the theory that the detainee might possibly not have been the perpetrator," federal prosecutor Peter Frank told reporters.

The style of attack and the target suggested Islamic extremism, he said.

The man detained, who has denied involvement, arrived in Germany from Pakistan at the end of last year.

He was captured in a park after reportedly fleeing the scene.

German Chancellor Angela Merkel, who laid flowers at the scene of the attack on Tuesday, vowed to punish those responsible "as harshly as the law requires".

Her open-door policy on migration, which saw 890,000 asylum seekers arrive in Germany last year, has divided the country, with critics calling it a security threat.

Several attacks carried out by refugees in July had already heightened tensions.

What happened?

The lorry ploughed through the popular market at Breitscheidplatz, near west Berlin's main shopping street, the Kurfuerstendamm.

Loaded with steel beams, it veered into the market at 20:14 local time (19:14 GMT), crashing through wooden huts and stands packed with tourists and locals.

Police believe the lorry drove 50-80 metres (160-260 ft) through the market area, Germany's DPA news agency reports.

Interior Minister Thomas de Maiziere said 18 of the 48 people injured in the attack were in a serious condition.

What do we know about the suspect?

He arrived in Germany on 31 December of last year, turning up in Berlin in February, Mr de Maiziere said. His asylum application had not been completed.

Citing security sources, German media identified him as Naved B, 23, who was reportedly known to police for minor crimes, but not terrorist links.

Special forces stormed a hangar at Berlin's defunct Tempelhof airport, where they believed he had been living in a shelter.

The suspect was seized near the Victory Column monument after allegedly fleeing the scene on foot for more than 2km (1.2 miles) towards the Tiergarten, a large public park.

Local newspapers say the driver of the lorry was followed by a bystander after jumping out of the cabin, and the man who tracked him used his mobile phone to keep in touch with police.

After Berlin police expressed doubt about whether they had in fact detained the right man, Mr Frank, the country's public prosecutor general, said: "Currently we don't know whether it was one or several perpetrators.

"We currently don't know whether he or they had support."

Berlin police chief Klaus Kandt said it was possible that there was a "dangerous criminal on the loose" and he urged vigilance.