Moscow - Russia said Thursday it would deploy more warships to battle piracy in the seas off the coast of Somalia, a top navy commander announced.

"After the Neustrashimy, Russia will be sending warships from other fleets to this region to the region," Admiral Vladimir Vysotsky said, alluding to a warship, the Fearless, now patrolling the coast, news agency Ria-Novosti reported.

The measures are being taken because of "the current situation off the Horn of Africa and the Gulf of Aden, where Somali pirates have sharply increased their activities," he said.

Piracy in the strategic shipping area has surged in recent months, peaking with the weekend seizure of a Saudi supertanker carrying crude oil worth 100 million dollars.

Moscow's decision came amid growing frustration that NATO ships patrolling the area have not been able to stem the incresingly bold hijackings.

Many shipping lines are now working to avoid the Gulf of Aden - a busy shipping channel which forms part of the route linking the Indian Ocean with the Mediterranean Sea through the Suez Canal.

Somali pirates who hijacked the Sirius Star, sailing under the Saudi flag, said Thursday they wanted 25 million dollars in ten-days to free their hostages.