lorry ploughed into a crowd at a Christmas market in Berlin on Monday night, killing nine people and injuring 50 others, Berlin police have announced.

9 killed, 50 injured in Berlin market truck crash.

The truck drove over the sideway at Breitscheidplatz,

a major public square near the location of the iconic Kaiser Wilhelm Memorial Church, in the inner city of Berlin, the police tweeted.

According to witnesses, people screamed and ran desperately for shelter after the truck veered towards the crowd near the Christmas market.

According to the police, the passenger of the truck died on the spot, while a suspicious person was arrested near Breitscheidplatz following the incident. "Whether it is the driver of the truck, is currently under consideration," the police tweeted.

The motive of the incident remains unknown. Police have begun investigations which point to a possible terrorist attack.

Police have cordoned off the area near the Kaiser Wilhelm Memorial Church and many police cars and ambulances are still in the area, according to a Xinhua reporter on the scene.

The police have also called on citizens in Berlin to stay at home and not to spread rumors.

The background of the incident is still unclear, the police added.

"We mourn the dead and hope that many injured people can be helped," German Chancellor Angela Merkel's spokesman Steffen Seibert tweeted on Monday night.

A series of attacks occurred in Germany in this summer, raising concerns over the safety of the country in the fallout of refugee influx in recent years.