German police said on Tuesday that they have ended an hours-long search at a luxury hotel in Leipzig after finding the identity of a caller who rang the hotel overnight warning of an imminent terror attack.

The caller had been one of a group of teenagers ringing by cellphone from Austria as a "joke," they tweeted.

"We are ending our police operation and can have a breather," they said.

During the operation, police armed with submachine guns had surrounded the building in the city center.

More than one hundred officers from the Saxon state police special forces were deployed together with sniffer dogs, and the entire building was searched, as well as vehicles near the Fürstenhof Hotel, a spokesman said earlier. Police said they did not evacuate the building to avoid panic.

German security forces are on high terror alert following two attacks in July in southern Germany that have been linked to the "Islamic State" extremist group.

tj/jil (AFP, dpa)