"The two men have surrendered to police," the official told AFP.

The plane with 113 passengers and crew on board was hijacked during a flight from Albania to Istanbul.

Italian civil aviation authorities told the ANSA news agency that the two apparently unarmed hijackers had a message for Pope Benedict XVI, who is due to visit mainly Muslim Turkey in late November.

Istanbul Vice-governor Vedat Muftuoglu said the hijackers took control of the plane 15 to 20 minutes after it took off from the Albanian capital Tirana.

"They said their action was to protest the pope's visit and that they wanted to go to Rome," Muftuoglu told CNN-Turk television, adding that the pilot said he did not have enough fuel to reach Rome and would have to land in the southeastern city of Brindisi.

However Turkish Transport Minister Binali Yildirim told a television channel that the hijackers were seeking political asylum and there are no indications that they are protesting against the pope's planned visit to Turkey.

"The information concerning the pope was not confirmed.... According to the information we just received these persons are seeking political asylum and have said so to the (Italian) police," Yildirim said.

An Italian aviation official said that the passengers remained aboard the plane, contradicting a report by the ANSA news agency that they had begun to leave the aircraft.

Speaking on the Italian news channel TG 24, the official said one crew member had left the plane.

Turkish Airline's chief executive Candan Karlitekin earlier told a Turkish television channel: "There is no threat at the moment to the passengers nor the crew. We believe the hijackers will surrender."