There were no injuries and all the divers were outside the danger zone when the explosion occurred. Video from the scene showed a huge explosion that threw a torrent of water into the air.
Some 750 people were evacuated from the surrounding area before the explosion.
Speaking to Polish news agency PAP, Lieutenant Grzegorz Lewandowski, spokesperson for the 8th Coastal Defense Flotilla, confirmed that the site is now secure.
He said: “The blast process turned into a blast. “The object can be considered neutralized, it will no longer pose a threat. “All mine divers were outside the danger zone.”Swinoujscie houses a liquid natural gas terminal, but it did not suffer any damage during the explosion.
However, on April 16 Lancaster bombers armed with Tallboy bombs targeted the cruiser.
They scored a direct hit on the Lutzow, as well as several close failures, causing her to sink. It is not known which of the three attacks the bomb that exploded was linked.
Despite the sinking, Lutzow’s main deck remained above the waterline and it was used as a floating cannon battery against Soviet troops as they advanced towards Germany. She was later bred by the Soviet Navy, then sunk as a target in July 1947.
The Tallboy Bomb was designed by Barnes Wallis, most famous for the invention of the “bouncing bombs” used in the Dambusters raid, as a weapon to be used against German ships and strong fortifications.
Its size meant it could only be worn by a specially modified version of the Lancaster Bomber. Most notably in November 1944, the German battleship Tirpitz was hit by three Tallboy bombs and sank, killing at least 940 sailors.
Poland was invaded by Germany in September 1939, forcing Britain and France to declare war. A few weeks later, the Soviet Union also invaded from the east. Poland spent most of the war under Nazi control before being occupied by Soviet troops, who installed a pro-Moscow Communist government.