EgyptAir plane that was hijacked and forced to land in Cyprus.

An EgyptAir plane that took off from the coastal city of Alexandria for Cairo has been hijacked and forced to divert to Larnaca airport in Cyprus.

Flight MS181 had 55 passengers on board when it was seized, Egyptian authorities said. Everyone on board has been released except for the captain and co-pilot, a female crew member, a security officer and three passengers. Negotiations with the hijacker are ongoing.

Officials at Alexandria airport told Associated Press that the hijacker was a dual Egyptian-American citizen. Cypriot media said he demanded to speak with a Cypriot woman to whom he claims he was once married. She is now being brought to the airport to participate in the negotiations. There were also unconfirmed reports that he had demanded the release of prisoners in Egypt.

Egyptian authorities said the hijacker had threatened to detonate an explosive belt, but did not know whether the belt was real or fake.

Addressing reporters with the visiting European parliament president, Martin Schulz, the Cypriot leader, Nikos Anastasiades, ruled out terrorism, confirming instead that it had been instigated a man bent on reuniting with his former wife.

“It’s all to do with a woman,” said the Cypriot president. “We are doing everything to release the hostages.”

Cyprus police said the control tower was contacted at 8.30am (5.30am GMT) and the plane was given permission to land at 8.50am.

A statement from the Egyptian civil aviation ministry said foreign nationals on board included eight Americans, four Britons, four Dutch, two Belgians, a French national, an Italian, two Greeks and one Syrian. Three other foreigners could not be identified. The nationalities of those who remained on the plane were not given.

The plane was hijacked 30 minutes into its flight, according to officials. Less than an hour later, local TV showed about 40 women and children being allowed to leave the aircraft. The freed passengers were then put on buses and taken to terminal buildings.

Cyprus, the nearest EU member state to the Middle East, immediately declared a state of emergency, with the ministers of defence, foreign affairs and transport all being dispatched to the airport within minutes of the plane making its forced landing.

Airport authorities said all scheduled flights into Cyprus were being diverted to the island’s second international airport at Paphos.

The hijacking is likely to bring to the fore again the question of security at Egyptian airports, five months after a Russian aircraft crashed over Egypt’s Sinai peninsula minutes after it took off from the Red Sea resort of Sharm el-Sheikh. All 224 people on board were killed in the crash. Russia later said an explosive device brought down the aircraft and the extremist Islamic State group said it downed the plane.