Police stand guard near the site of a lorry crash at a Christmas market in Berlin, Germany, Dec 19, 2016. A 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. [Photo/Xinhua]

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.