ANKARA, Turkey - Nine people were killed in eastern Turkey by a magnitude 5.7 earthquake early Sunday morning, Turkish Health Minister Fahrettin Koca said.

The quake centred just east across the border in neighbouring Iran, west of the Iranian city of Khoy, and affected villages in the Turkish province of Van.

At least three of the dead were children, according to Turkish Interior Minister Suleyman Soylu. The health minister later said at least 37 people were injured, including nine in critical but not life-threatening condition.

Iran's official IRNA news agency said at least 75 people had been injured inside Iran, six of whom were hospitalized.

A second earthquake - also magnitude 5.7 - struck Sunday evening in the same area in Iran, according to the country's seismology centre.

It was not immediately clear if the second quake caused further damage or casualties in either country.

The U.S. Geological Survey put the second earthquake's magnitude at 6.0. Varying magnitudes are common in the immediate aftermath.

Turkish broadcaster NTV showed images of locals and soldiers digging through the rubble of collapsed buildings on Sunday, as families sat in snowy streets fearing further tremors.

Emergency teams were sent to the remote mountainous region, which has a history of powerful earthquakes. Last month, a quake centred on the eastern Turkish city of Elazig killed more than 40 people. In 2011, more than 600 were killed when a quake struck north of Van province's capital.

According to the European Mediterranean Seismological Center, the first quake happened at 9:22 a.m. local time (0552 GMT) at a depth of 5 kilometres (3 miles). The EMSC reported several further quakes that measured up to magnitude 4.4.

Iran's seismology centre said the second quake hit the Zarabad district at at 7:30 p.m. local time (1600 GMT) at a depth of 28 kilometres (17 miles).

The USGS said the first quake was at a depth of 6.4 kilometres (4 miles) and the second was at 10 kilometres (6 miles).

The effects of the quake hit four villages in Van. Seven of the fatalities occurred in Ozpinar village, where Soylu said search and rescue teams had arrived. He added that the quake caused 1,066 buildings to collapse while the Education Ministry said a number of schools were damaged.

Koca said 25 ambulances, a medical helicopter and 13 emergency teams had been sent to the region. The Disaster and Emergency Management Directorate (AFAD) said 144 tents for families had been dispatched.

IRNA said the first earthquake affected 43 villages in the mountainous Qotour area.

Associated Press writer Amir Vahdat contributed to this report from Tehran, Iran.