A bomb threat to an Israel-bound cruise ship prompted a security operation at the Greek island port of Syros on Tuesday after an unknown person claimed an explosive device had been attached to its hull, Greek authorities said.

The Panama-flagged Crown Iris was due to sail to Haifa carrying 940 passengers and 597 crew members when the threat was received.

Coast guard personnel assisted by an explosives detection dog and a private diver searched the vessel, while a special coast guard unit was deployed to the scene.

Initial checks found no explosive device. Coast guard specialists are expected to arrive at 9.30 p.m. (1930 GMT) to carry out further inspections before the ship can resume its voyage.

At least seven flights in Europe received bomb threats on Tuesday, causing disruption at airports although no devices were discovered.