5.7-magnitude earthquake shakes Istanbul

A 5.7-magnitude earthquake shook Turkey's largest city on Thursday, driving residents to evacuate buildings, AFP journalists witnessed.

The quake's centre was in the town of Silivri in Istanbul province, Istanbul's Bogazici University Observatory and Earthquake Research Institute said, measuring it at magnitude 5.7.

There were no immediate reports of damage, but many schools and offices were evacuated.

Istanbul lies near a major faultline and experts have forecast that a severe earthquake is due there in the coming years.

A large quake could devastate the city of 15 million, which has allowed widespread building without safety precautions.