Ukraine opened an investigation into a terrorist threat after Friday's hijack attempt by a Ukrainian man on a Turkish airliner, the country's chief of investigations, Maksym Lenko, told reporters Saturday.
The suspect said there was "a bomb on board," Turkish officials said, and he tried to divert the plane to Sochi, Russia -- the site of the Winter Olympics.
The Ukrainian foreign ministry said no explosives or guns were found on board.
The man, who was not named by Ukrainian authorities, is from the Ukrainian city of Kharkov, where he bought a plane ticket and boarded the Pegasus Airlines flight that left for Istanbul on Friday afternoon with 110 passengers on board, Lenko said.
According to Lenko, witnesses said the man tried to enter the cockpit and demanded the plane change route to Sochi, where "there are (Russian President Vladimir) Putin and (Ukrainian President Viktor) Yanukovych, whose hands got blood on them."
Witnesses said the other demand was to "free hostages in Ukraine," Lenko said.
The pilots tricked him by turning the plane twice, and the suspect calmed down once he thought his demand was being met, Lenko said. The plane then landed safely.
The Ukrainian foreign ministry said no one was injured and the suspect voluntarily turned himself in to police, but the Istanbul governor had a different story.
Gov. Huseyin Avni Mutlu said special forces boarded the plane during the evacuation of passengers and used force to take the suspect into custody.
"We had to use force because we were trying to persuade him and he wasn't persuaded," Mutlu said. "Without using guns, force was used. He has a light injury."
The suspect had a carry-on bag with some electronics, the governor said, and may have been under the influence of "substances."
"He thought for a while he was going to Sochi, but after a while he realized he was in Istanbul," he said.
The suspect was not able to enter the cockpit, and no bomb was found on him, he said.
Ukrainian Embassy officials in Istanbul were expected to meet the suspect who was taken into custody by Turkish authorities after the plane safely landed in Istanbul, Lenko said.
Ukrainian investigators are also trying to determine the suspect's motive for the hijacking attempt, whether he was drunk and why he chose that particular flight.