By Nathan Morley
Video footage from the region posted online showed collapsed buildings and vehicles destroyed by falling debris.
In a statement, the US Geological Survey said the shallow tremor measured 7.0 on the Richter Scale. Turkey lies on several of fault lines and is prone to earthquakes.
Search and rescue operations are ongoing in the ruins of eight buildings, despite a total of 470 aftershocks having occurred since the main tremor.
According to the Disaster and Emergency Management Authority of Turkey, the death toll in the western province of Izmir increased to 25.
A total of 804 people were wounded by the tremor. Some 100 survivors have been pulled out alive from the debris so far.
Up to 5,000 emergency service workers and 20 search and rescue dogs have been taking part in the rescue effort.
The quake also shook Greece's Island of Samos where two high school students died and at least eight people were injured.