BRATISLAVA, Slovakia (AP) — The discovery of a World War II bomb in Slovakia's capital during construction work prompted evacuations on Tuesday, officials said.

The emergency measure covered several blocks in downtown Bratislava, including a major bridge across the Danube River. Public transportation and all traffic were halted during the morning rush hour.

Experts were planning to defuse the 500-pound (225-kilogram) bomb, which was discovered on Monday evening, by midday.

An oil refinery located in the area was a target of the Allied bombardment in 1944 during the war. Slovakia was a Nazi puppet state during World War II.