NICOSIA, Cyprus - An EgyptAir plane was hijacked on Tuesday by a single assailant with unclear motives.

EgyptAir flight MS181, flying from the Egyptian Mediterranean coastal city of Alexandria to the capital, Cairo, was diverted and landed safely in Larnaka, Cyprus. The incident ended almost four hours later with the single suspect's arrest in Larnaka, and no reported casualties.

The jet had 81 passengers on board and was flying on a regular domestic route when the hijacking took place, Egyptian officials said. There was conflicting information about the total passenger count from the airline, however, suggesting fewer travelers.

The airline said a passenger threatened pilot Omar al-Gammal during the flight, telling him he had a suicide belt, and demanding the plane be re-routed.

EgyptAir said in a tweet that negotiations with the hijacker lead to the release of all passengers on board with the exception of four non-Egyptian nationals.

At a news conference several hours after the ordeal began, Egypt's Minister of Civil Aviation, Sherif Fathi, said there were still seven people on the plane, in addition to the hijacker. He said the captain and co-pilot, a security officer, three passengers and a flight attendant remained on the plane.

Earlier the ministry said there had been 21 foreign passengers on the flight, including eight Americans. The nationalities of those still on the jet was not immediately clear, but U.S. officials told CBS News all American passengers had made it safely off the aircraft.

About four hours after the plane touched down, Cyprus' Ministry of Foreign Affairs said the suspect had been taken into police custody and the incident was over.

Officials at the Egyptian airport from which the hijacked aircraft took off said the hijacker was a native of the Egyptian Mediterranean city of Alexandria and a dual Egyptian-American citizen.

Cyprus' Ministry of Foreign Affairs identified the hijacker in a message sent on Twitter as Egyptian national Seif El Din Mustafa. No further information was given about Mustafa and there was no mention of any dual nationality.

The Associated Press contributed to this report.