Tens of thousands were evacuated from a German city Wednesday after the discovery of three unexploded bombs in the city center left over from WWII .

The operation in Cologne, located in western Germany, is the largest evacuation in the city since the end of the fighting in Europe in 1945, city officials said. More than 20,000 people including residents, workers and hotel guests were cleared from parts of the city's old town and central Deutz district, Reuters reported, spanning a zone slightly larger than a half-mile.

The evacuation began at 8 a.m. local time, impacting morning commutes in a bustling riverfront area of the city. Three American bombs, each with impact fuses, were found Monday, June 2 during construction work in a shipyard on the bank of the Rhine River, according to a

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