Security will be tightened around Werder Bremen's home Bundesliga clash against second-placed VfL Wolfsburg on Sunday after police warned of a possible terrorist attack in the Hanseatic City.

Bremen police have specifically warned about Islamic terrorists at large in the city on Saturday morning, while there has been a nationwide alert to potential terrorist activity since Friday night.

Werder Bremen's spokesman has said the league match will not be postponed, but the club are in constant contact with the police's operations centre and security measures will be stepped up for the game.

The match is one of the league's top clashes this weekend with Bremen unbeaten in their last six outings which has taken them from last to eighth.