Thousands of people, some of them shaken, were evacuated Wednesday from a neighbourhood of Germany's financial capital Frankfurt following the discovery of a massive World War II bomb.

City authorities said 25,000 people were evacuated from the densely populated Nordend area after the 500 kilogramme bomb was unearthed during construction work.

Bomb disposal teams are due to detonate the explosive once they cover it with soil, the authorities said.

People sheltering at a skating rink expressed concern about the latest discovery of a World War II bomb, which still occurs regularly 76 years after the war's end.

Tobias, 29, said he heard the news over a police loudspeaker.

With his pet cat in a cage, he confessed he felt a "bit of stress" when he was ordered to leave his home immediately.

Barbara, 77, said she heard it the radio.

"It was a bit of a shock, we don't expect that," she told AFP, adding she wanted to return home as soon as possible.

Germany is littered with unexploded World War II ordinance that is often found on work sites.

Seven bombs were defused in 2020 on land near Berlin where Tesla plans to build its first factory in Europe for electric cars.   

Other bombs were also discovered last year in Frankfurt, Cologne, and Dortmund. 

In 2017, the discovery in Frankfurt of a 1.4 tonne bomb led to the removal of 65,000 people, the biggest such evacuation in Europe since 1945.