The following copied from Airliners.net:
Aviation Herald is posting the following regarding the hijacking. Looks like it ended peacefully.
A Pegasus Airlines Boeing 737-800, registration TC-CCP performing flight PC-751 from Kharkov (Ukraine) to Istanbul Sabiha Gokcen (Turkey) with 110 people on board, was enroute at FL370 about 285nm northeast of Sochi (Russia) and about 50nm north of Simferopol (Russia) when the crew activated the transponder code for unlawful interference. Turkish fighter aircraft were dispatched to accompany the aircraft to Istanbul. The aircraft maintained the unlawful interference squawk until after landing in Istanbul Sabiha Gokcen Airport about one hour later and taxied to a remote secure area. Turkish security forces entered the aircraft and arrested one of the passengers.
The airline confirmed a safety related incident involving a bomb threat on board of their flight PC-751.
Passengers reported a passenger claimed to have a bomb and wanted the aircraft to divert to Sochi where the opening ceremony of the Winter Olympic Games 2014 were in progress. The man subsequently tried to enter the cockpit but did not succeed.
Turkish security forces were deployed to Sabiha Gokcen Airport and arrested a passenger, a search for explosives was initiated.