German city evacuates 20,000 people to defuse WWII bomb

A excavator at work at the location of a WWII one-tonne bomb near the Muelheim bridge in Cologne, Germany, on May 27, 2015. About 20,000 people were forced to leave their homes while the bomb was made safe. -- PHOTO: EPA
A excavator at work at the location of a WWII one-tonne bomb near the Muelheim bridge in Cologne, Germany, on May 27, 2015. About 20,000 people were forced to leave their homes while the bomb was made safe. -- PHOTO: EPA
Ambulances wait at a social services facility after a WWII one-tonne bomb was discovered near the Muelheim bridge in Cologne, Germany, on May 27,  2015. -- PHOTO: EPA
Ambulances wait at a social services facility after a WWII one-tonne bomb was discovered near the Muelheim bridge in Cologne, Germany, on May 27,  2015. -- PHOTO: EPA
Worker's of Germany's Arbeiter Samariter Bund ASB, a welfare organisation engaged in civil protection, rescue and social services line up handicapped pensioners to evacuated a nearby nursing home in a special bus in Cologne, Germany, on May 27, 2015.
Worker's of Germany's Arbeiter Samariter Bund ASB, a welfare organisation engaged in civil protection, rescue and social services line up handicapped pensioners to evacuated a nearby nursing home in a special bus in Cologne, Germany, on May 27, 2015. -- PHOTO: REUTERS
Disarmed World War II bomb is pictured on the platform of a truck near Muehlheim Bridge in Cologne, western Germany, on May 27, 2015. -- PHOTO: AFP
Disarmed World War II bomb is pictured on the platform of a truck near Muehlheim Bridge in Cologne, western Germany, on May 27, 2015. -- PHOTO: AFP

BERLIN (AFP) - German authorities evacuated around 20,000 people from their homes in the western city of Cologne Wednesday before defusing a World War II bomb unearthed during construction work.

Residents living within a kilometre (about half a mile) of the site were told to leave their homes, among them around 1,100 people from a large old people's and care home, city officials said.

Schools in the area as well as Cologne Zoo, also within the danger zone, were closed for the day.

The unexploded US-made device, which lay five metres (16 feet) underground, was discovered on Friday on the left bank of the Rhine river near Muelheim bridge, city officials said.

Hundreds of police, firefighters and other helpers were involved in clearing the area for the city's largest evacuation since the end of the war.

River traffic had to be halted during the afternoon operation to de-activate the one-tonne bomb, while the airspace above the zone was also closed.

"Everything went well," Cologne city hall said in a statement afterwards, adding that the bomb was "successfully defused".

Residents began returning to their homes in the early evening.

Seventy years after the end of fighting, parts of Germany remain riddled with unexploded bombs from the Allied campaigns, and construction workers regularly stumble upon them.