By Yiannis Kourtoglou and Nadia El Gowely
Conflicting theories have emerged about the motives of an Egyptian man who hijacked an EgyptAir plane while wearing a fake suicide belt, forcing it to land in Cyprus, before giving himself up.
Eighty-one people, including 21 foreigners and 15 crew, had been on board the Airbus 320 when it took off from Alexandria en route to Cairo on Tuesday, Egypt's Civil Aviation Ministry said in a statement.
A senior Cypriot official said the man was psychologically unstable and the incident did not appear related to terrorism, while the Cypriot state broadcaster said the man had demanded the release of women prisoners in Egypt.
In the midst of the crisis, witnesses said the hijacker had thrown a letter on the apron at Cyprus's Larnaca airport, written in Arabic, and asked that it be delivered to his Cypriot ex-wife.
After the aircraft landed at Larnaca, negotiations began and everyone on board was freed except three passengers and four crew, Egypt's Civil Aviation Minister Sherif Fethy said.
Soon afterwards, Cypriot television footage showed several people leaving the plane via the stairs and another man climbing out of the cockpit window and running off.
The hijacker then surrendered to authorities.
"Its over," the Cypriot foreign ministry said in a tweet.
Egyptian Prime Minister Sherif Ismail said the hijacker would be questioned to ascertain his motives.
"At some moments he asked to meet with a representative of the European Union and at other points he asked to go to another airport but there was nothing specific," he said.
Egypt's Civil Aviation Ministry said the pilot, Omar al-Gammal, had told authorities that he was threatened by a passenger who claimed to be wearing a suicide explosive belt and forced him to divert the plane to Larnaca.
Reached by telephone, Gammal told Reuters that the hijacker seemed "abnormal".
"I am not in a state to speak," said the exhausted-sounding pilot, adding that he had been obliged to treat the suicide belt as a serious security threat.
Photographs shown on Egyptian state television showed a middle-aged man on a plane wearing glasses and displaying a white belt with bulging pockets and protruding wires.
Television channels showed video footage of the hijacker, identified as Seif Eldin Mustafa, 59, being searched by security men at a metal detector at Borg al-Arab airport in Alexandria.
Interior Ministry officials said he was expelled from law school and had a long criminal record, including robberies.
Fethy, the Egyptian minister, said authorities suspected the suicide belt was not genuine but treated the incident as serious to ensure the safety of all those on board.
"Our passengers are all well and the crew is all well ... We cannot say this was a terrorist act... he was not a professional," Fethy told reporters after the incident.
The incident will deal another blow to Egypt's tourism industry and hurt efforts to revive an economy hammered by political unrest following the 2011 uprising that ousted veteran ruler Hosni Mubarak.