BERLIN,Dec. 20 (Xinhua) -- Due to a bomb threat, a shopping arcade and a Christmas market have been cleared in German city Heide. The threat came on Thursday morning via e-mail, local media, Focus online, cited a police spokesman as saying.

About 30 police officers closed the shopping area and also cleared the adjacent Christmas market. Police launched investigation into the sender of the mail.

Focus online said, in recent days, bomb threats have kept local task forces in the state of Schleswig-Holstein busy. In Flensburg, Lubeck and Itzehoe, some buildings have been evacuated, without any suspicious objects being found.

The police will check if there is a connection between these acts, local media said.