Small magnitude temblors continue following the 4.4 earthquake in the Sea of Marmara recently.
The Istanbul-based Kandilli seismology centre says the quake occurred at 02:37 and 06:38 Friday.
Prmime Ministry Disaster and Emergency Management Directorate announced the preliminary magnitudes of the temblors as 2.6.
An earthquake with a preliminary magnitude of 4.4 struck northwestern Turkey on Oct. 3.
but there were no reports of damage or injuries.
The Kandilli seismology centre says the quake occurred at 8:49 p.m. (1749 GMT) Sunday. Its epicenter was in the Sea of Marmara.
The quake was felt in Istanbul, Turkey's largest city.
Earthquakes are frequent in Turkey, which is crossed by faultlines.
In 1999, about 18,000 people were killed two powerful earthquakes that struck northwestern Turkey.