At least 217 people have been killed and hundreds more remain trapped under rubble after a powerful earthquake struck southeast Turkey, Sky News reported.
Dozens of buildings were destroyed by the 7.2 magnitude quake near the city of Van and the town of Ercis, close to the Iranian border.
Tens of thousands of people rushed into the streets after the first tremor and were digging with shovels and their bare hands to free those trapped.
US scientists recorded over 100 aftershocks in eastern Turkey within 10 hours of the quake, including one with a magnitude of 6.0.
Authorities advised people to stay away from damaged homes, warning they could collapse in the aftershocks.
Interior minister Idris Naim Sahin said at least 100 people were killed in Van, 117 others died in Ercis, and around 1,090 were injured, local TV channels reported.
But officials estimate the death toll could rise to 1,000 as many people remain unaccounted for.
Deputy prime minister Besir Atalay said: "Around 10 buildings have collapsed in the city of Van and around 25 or 30 have collapsed in Ercis, including a dormitory."
Around 1,275 rescue teams from 38 provinces have been sent to the region, officials said, and troops were also assisting search-and-rescue efforts.
In Ercis, heavy machinery was halted and people were told to stay quiet as rescuers listened out for sounds within the rubble.
Residents lit campfires to keep warm as they spent the night outdoors while others took refuge in tents set up in a sports stadium.
A nurse at a public hospital said hospital workers were treating the wounded in the hospital garden because the building was badly damaged.
International offers of aid poured in from Nato, China, Japan, the US, Azerbaijan, European countries and Israel.
Mr Erdogan thanked the governments who had offered help, but said Turkey could handle the disaster relief efforts without assistance.