A secondary quake measuring 7.3 on the Richter scale struck the Altai territory with its epicentre in a mountainous region 350 kilometresmiles) south of the capital Barnaul, Rossia television said.

Some houses were destroyed, but there was no information on casualties, the television said.

Separately, two strong shocks were recorded in the neighbouring Altai republic which borders Mongolia, one shortly before midnight local time and the second in the early hours of Sunday, the ITAR-TASS news agency said.

Although the epicentre was in the mountains, several houses and buildings were destroyed and officials in the republic's capital Gorno-Altaisk declared a state of emergency, the agency said.

The shocks measured between five and six on the Richter scale, the agency said, quoting local officials.

The region recorded around 100 tremors, most of them minor, following Saturday's quake in Mongolia, and local hospitals had been evacuated in advance of the larger shocks.

Many of Gorno-Altaisk's 70,000 inhabitants spent the night outdoors, ITAR-TASS said.

The Earth Sciences Laboratory at Strasbourg, in eastern France, earlier reported a shock measuring 7.3 on the Richter scale in Western Siberia at 01.52 Sunday local time (1852 GMT Saturday).

This followed a quake that struck the region at 19.33 Saturday local time (1133 GMT) that was felt in many cities of Western Siberia including Novosibirsk, Krasnoyarsk and Tomsk and in the north of neighbouring Kazakhstan.

There have as yet been no reports of casualties, but emergency teams and rescue planes and helicopters have been placed on alert.

TERRA.WIRE