But worst affected were the high-altitude villages of south Kyrgyzstan where one settlement was destroyed completely and the fate of a scattering of others remained unclear.

"The total number of dead is now 72," Deputy Health Minister Madamin Karatayev said through the ministry's press service.

This included 30 children who were not yet of school age, 11 students, 12 pensioners and 19 adults, he said.

Three helicopters had transported 110 wounded children and adults to a hospital in the regional centre of Osh.

Karatayev added that most houses in the Nura village on Kyrgyzstan's border with China had been destroyed completely, including traditional clay huts.

As darkness fell, rescue teams continued their search under arc lights and were prepared to work through the night, he said.

Severed from more populated areas by treacherous mountain passes, the villages were difficult to reach quickly. Rescue efforts were also hampered by poor communications.

"It's difficult to extend all the necessary help, there is no telephone connection," said Yelena Bayalinova, a health ministry spokeswoman. "Many have multiple injuries, broken limbs, they are in a state of shock".

CONDOLENCES FROM RUSSIA

Russian President Dmitry Medvedev, due to visit Kyrgyzstan later this week, sent his condolences in a telegram and said Moscow, which operates a military air base in Kyrgyzstan, was ready to provide humanitarian assistance.

Kyrgyz President Kurmanbek Bakiyev announced that Tuesday will be a national day of mourning, when he will fly to the Nura settlement to assess the rescue effort and console the families affected.

Earthquakes are frequent in Central Asia, a region set between Afghanistan, Iran, Russia and China.

In 1966, the Uzbek capital Tashkent was flattened by a 7.5 earthquake when hundreds of thousands of people were left homeless. A 6 magnitude quake rocked Tashkent this August but there was no damage.

Strong earthquakes hit China's remote western regions of Xinjiang and Tibet on Monday.

The quake in Tibet was a magnitude 6.6 tremor that hit at 4.30 p.m. local time (0830 GMT) around 80 km (50 miles) west of the regional capital Lhasa, the US Geological Survey said on its website (http://earthquake.usgs.gov).

Residents in the city said they had felt the quake, but there was no visible damage. Closer to the epicentre, in the county of Qushui, buildings shook and windows rattled but a hospital official said there were no reports of any injuries.

It was followed around 15 minutes later by a 5.1 magnitude shock in a similar area.

(Writing by Maria Golovnina; editing by Ralph Boulton)