WARSAW, Poland - Authorities in northwest Poland are mulling the evacuation of some 42,000 people after a giant British World War II seismic bomb was found buried in the waterway leading to the port of Szczecin.

The 5.5-ton Tallboy bomb is 6 metres (20 feet) long and was found during works in a channel running through the town of Swinoujscie to Szczecin. With an impact range of over 10 kilometres (6 miles), it is the biggest wartime bomb found in Poland’s waters.

Agnieszka Muchla-Lagosz, a regional spokeswoman, said experts are discussing ways of removing the bomb and the possible need to evacuate all residents of Swinoujscie.

Tallboy bombs were used from June 1944 by British forces to destroy especially hard structures. The region was then under German control and heavily bombed.