"Russian cosmonaut Salizhan Sharipov and American astronaut Leroy Chiao have been advised to stay in the most radiation-protected place aboard the station, especially when it is facing the sun," the agency quoted a Russian official as saying.

It quoted Valery Bogomolov, deputy director of Moscow's Institute of Biomedical Problems, as saying that the magnetic storm posed no danger to the health of the crew.

Physicians nonetheless advised Sharipov to sleep in a well-protected portion of the Russian service module while Chiao has continued to sleep in his usual berth in the US module Destiny, the report said.

ITAR-TASS said "the alert regime envisages the intensified monitoring of radiation outside the space station" using several special instruments.

The agency quoted another official as saying that the strongest surge of charged particles to be measured by the station since November 2003 was recorded Monday.

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