Turkey has been hit by a second massive earthquake, hours after an earlier catastrophic quake devastated the region and killed more than 1,600 people.

The 7.8-magnitude night-time tremor, followed hours later by a slightly smaller one, wiped out entire sections of major Turkish cities in a region filled with millions of people who have fled the civil war in Syria and other conflicts.

The later 7.5 magnitude quake struck at 1.24pm (1024 GMT) two-and-a-half miles southeast of the town of Ekinozu and around 60 miles north of the first quake that has wrought devastation across Turkey and Syria.

Hundreds are still believed to be trapped under rubble on both sides of the border as a result of the first, and the toll is expected to rise as rescue workers continue to search through mounds of wreckage for families crushed in their sleep.

Orhan Tatar, an official from the Turkish disaster agency, told reporters that the two quakes were independent of each other. He said hundreds of aftershocks were expected after both. Tremors were felt as far away as Greenland.