A truck which ploughed into a crowded Christmas market in Berlin was deliberately crashed in a suspected terrorist attack, police said.

Twelve people died and 48 were injured - some seriously - when the vehicle rammed into a market taking place outside the Kaiser Wilhelm Memorial Church on Monday evening.

Berlin Police said on Twitter on Tuesday morning that the incident was intentional and a suspected act of terrorism.

German police said a passenger in the truck died at the scene, and a suspect, believed to be the driver, was arrested nearby after the vehicle crashed into the market outside the capital's popular market at the Kaiser Wilhelm Memorial Church.

It came less than a month after the US State Department called for caution in markets and other public places, saying extremist groups including Islamic State and al Qaida were focusing 'on the upcoming holiday season and associated events'.

IS and al Qaida have both called on followers to use trucks in particular to attack public places.

On July 14, a truck ploughed into a Bastille Day crowd in the southern French city of Nice, killing 86 people. IS claimed that attack, which was carried out by a Tunisian living in France.

Mike Fox, a tourist from Birmingham, said the truck missed him by about three metres as it drove into the market.

'It was definitely deliberate,' he said, adding that he helped people who appeared to have broken limbs, and that others were trapped under Christmas stands.

Dozens of ambulances lined the streets waiting to take the injured away, and heavily armed police patrolled the area

olice on Twitter urged people to stay away from the area, saying they need to keep the streets clear for rescue vehicles.

The truck was registered in Poland, but officers are still investigating where it came from and who the driver was.

The Polish owner of the truck said he feared the vehicle, originally driven by his cousin, may have been hijacked. Ariel Zurawki said he last spoke with the driver around noon, and was told he was in Berlin and scheduled to unload on Tuesday morning.

Television footage showed a large Scania truck with its windscreen smashed on the pavement alongside the market. A large Christmas tree with a gold star on top was toppled over nearby in the street.