A 200 kg World War II bomb was discovered on Monday at the construction site of the new NATO headquarters in Brussels, a police representative said.
Traffic was diverted from Leopold III Avenue, where the building is being constructed, while sappers attempted to demine the bomb.
The demining work, which stopped when it got dark, will resume on Tuesday.
The construction of the new NATO headquarters, which will cost an estimated 460 million euros ($626 million), began in September and is expected to be concluded by fall 2015.
The new building, which will occupy 250,000 square meters, is being constructed about 100 meters from the current NATO headquarters.
BRUSSELS, November 15 (RIA Novosti)