Exercises being conducted this week between the Indian and Russian navies in the Indian Ocean are designed to send a signal to China in the face of its rising influence in the region, a senior naval officer said.

Warships from the two countries have been engaged since Thursday in exercises such as gunnery, air defence, anti-submarine and communication and seamanship evolution off India's west coast near Bombay, the country's financial hub.

The four Russian warships taking part in the three-day drill are to head to the southern port of Visakhapatnam for further exercises with India's eastern naval fleet in June.

"The Russians are here after 10 years. They are looking for strategic futures and would like to boost their military presence in the Indian Ocean as the break-up of the Soviet Union is now behind them," Rear Admiral Vijay Shankar said Thursday aboard the Indian warship INS Mysore, one of those taking part in the exercise.

The last major exercise between the two navies was conducted in 1993.

"The joint exercise is also a way to explore new ways to rebuild trade between the two friendly countries. For any successful trade the waterways have to be protected and we have to make our presence felt in the sea," Shankar said.

During a visit to Moscow earlier this month, Indian Foreign Minister Yashwant Sinha raised key areas of concern between the two countries such as weak physical and financial infrastructure which, he said, could be addressed only through better transport links and faster clearance of goods.

Last December, Indian Prime Minister Atal Behari Vajpayee and Russian President Vladimir Putin signed a joint declaration to strengthen economic, scientific and technological cooperation.

Bilateral trade between the two countries has fallen drastically to around 1.4 billion dollars at present, from more than four billion dollars before the break-up of the Soviet Union.

"Trade is the lifeblood of an economy. It is now an important mission of the navy to defend trade," Shankar said.

"Oil is the key to energy security, especially for a country like India. Nearly 55 percent of oil and petroleum products is transported through the Persian Gulf to India. We need a strong navy to police these waterways."

"We have to take care of ourselves and our one billion people. For this, military presence in the Indian Ocean has to be boosted also looking at the rising influence of China."

He said the rising military presence of China in and around India was emerging as a cause of worry.

"China is building a port in Baluchistan in Pakistan and chances are they would keep full military presence there," Shankar told AFP.

"China also has military facilities at Myanmar's Coco Islands. These are indications of a growing Chinese influence in the region." The Coco Islands are just 30 kilometers (18 miles) from India's Andaman island chain.

The ongoing exercise with the Russian navy is an attempt to enhance the Indian navy's operational capabilities given its changing role.

"At the operational level, the idea is to understand the inter-operational abilities of the two navies," said Arvind Raj Vardhan, captain of the INS Mysore.

"We have many benefits as we get an insight as to how they man their ships, understand their new technology and communication equipment and see how our interests are protected."

The two countries are also discussing the sale of the 44,500-tonne Russian aircraft carrier Admiral Gorshkov to the Indian navy as part of a package under which Moscow would also lease Turpov-22M3 long-range strategic bombers and Akula class nuclear-powered submarines to New Delhi.