German police are questioning a man they believe ploughed a lorry into a busy Christmas market in the heart of Berlin, killing 12 people and injuring 48.
The driver is an Afghan or Pakistani asylum seeker, according to security sources cited by DPA news agency.
He reportedly arrived in Germany in February as a refugee.
The daily Tagesspiegel said the man was known to the police for minor crimes, but not terror links.
German politicians have avoided branding the bloodshed a suspected terror attack at this stage, but interior minister Thomas de Maiziere told ARD television, “there are many things pointing to one”.
Berlin Police said investigators were treating the crash as a deliberate act.
The stricken market is at Breitscheidplatz, close to the Kurfuerstendamm, the main shopping street in Berlin’s west.
The deadly incident unfolded in the shadow of the Kaiser Wilhelm Memorial Church, which was damaged in a World War Two bombing raid and preserved as a symbol of peace.
The truck, which was loaded with steel beams, veered into the market at one of its busiest times, crashing through wooden huts and stands packed with tourists and locals.
The lorry driver was reportedly seized after leaving his truck and fleeing the carnage on foot.
Berlin police spokesman Winfried Wenzel told the German newspaper die Welt that the man ran down the street towards the Tiergarten, a large public park.
A witness followed him at a distance for over a mile (2 km), and called the police, who quickly detained him near the Victory Column monument.
The police spokesman speculated that the driver may have wanted to “find shelter in the darkness of the park”.
Police confirmed that a passenger was found dead in the lorry, and said he was a Polish national. There are fears he may have been the original driver of the vehicle, and that he was subject to a hijacking.
Ariel Zurawski, the Polish owner of the lorry, confirmed that his driver was missing and had been unreachable since 16:00 (15:00 GMT) on Monday.
“We haven’t heard from him since this afternoon,” he told the AFP news agency.
“We don’t know what happened to him. He’s my cousin, I’ve known him since I was a kid. I can vouch for him.”
Chancellor Angela Merkel has been briefed by the interior minister and the mayor of Berlin, her spokesman Steffen Seibert tweeted.
“We are in mourning for the dead and hope that the many injured can get help,” he added.
According to the DPA news agency, police believe the lorry drove 50-80 metres (54-87 yards) through the market area during the incident, which occurred at 20:14 local time (19:14 GMT).
A British eyewitness, Mike Fox, told Associated Press at the scene that the 25-tonne lorry had missed him by only about 3m as it smashed through stands and tore down a large Christmas tree.
“It was definitely deliberate,” said the tourist, visiting from Birmingham.
He said he had helped people who appeared to have broken limbs, and that others were trapped under Christmas stands.
Australian Trisha O’Neill told the Australian Broadcasting Corporation she witnessed “blood and bodies everywhere”.
“I just saw this huge black truck speeding through the markets crushing so many people and then 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.”
Join GhanaStar.com to receive daily email alerts of breaking news in Ghana. GhanaStar.com is your source for all Ghana News. Get the latest Ghana news, breaking news, sports, politics, entertainment and more about Ghana, Africa and beyond.
(Via: CitiFM Online Ghana)