Experts on Sunday destroyed a large World War II naval mine found by chance in a northern Croatian port, prompting hundreds of residents to be evacuated, officials said.

The 150-kilo (330-pound) mine, laid by German forces more than 80 years ago during WWII, was uncovered during construction work at the Rijeka port in June.

The explosive device had not been noticed earlier as it was partially buried in the muddy seabed at a depth of about 50 metres, officials have previously said.

Traffic was halted and some 500 residents of the area where the mine was found were evacuated for safety reasons ahead of the operation, conducted by special police divers helped by the army, according to an AFP photographer.

The mine was towed from the port to the Rijeka bay where it was successfully destroyed, according to local civil protection official Hinko Mance.