Berlin, Dec 1 (IANS/EFE): About 16,500 people were evacuated from the German city of Dortmund while experts deactivated a 1.8-tonne bomb from World War II that was found during construction work.

After evacuating residents Sunday, blocking all access routes to the site and establishing a no-fly zone overhead, bomb squad personnel began the defusal procedure.

The HC 4000 bomb, which was found Nov 26, was three metres long, 80 centimetres wide and packed with 1.5-tonnes of explosives.

The city authorities said that about 1,000 people took part in the operation, which included the evacuation of a refugee centre in the zone.

Around 700 of the refugee centre's residents were moved to a municipal facility and the area around the bomb site was cordoned off.

Experts also found three other incendiary bombs, each weighing about 15-kg buried near the first one, all of which were defused before the initial one was dealt with.

Also in the German city of Mainz, a 500-kg bomb was defused Sunday in another operation complicated by the fact that its outer covering had been damaged.

This operation, which was successfully completed, forced authorities to evacuate some 8,500 people and to halt river traffic along the river Rhine.