The quake was felt in the capital Ankara and other Turkish cities, and also across the region.
Reports are coming in that several buildings have collapsed, and a number of people may be trapped.
A BBC Turkish correspondent in Diyarbakir reports that a shopping mall in the city collapsed.
Rushdi Abualouf, a BBC producer in the Gaza Strip, said there was about 45 seconds of shaking in the house he was staying in.