An unexploded World War II bomb has been discovered in the immediate vicinity of Borussia Dortmund's stadium and authorities have evacuated the area.

Because the stadium was also inside the evacuated area, the club relocated the news conference of coach Juergen Klopp ahead of the Ruhr Derby against Schalke to another facility.

Dortmund authorities say the 250-kilogram (550-pound) bomb was British and would be disarmed later Thursday. It was discovered on a building site next to the stadium.

Unexploded ordnance from WWII is still frequently found in Germany.