The Neustrashimy (Fearless) frigate arrived at the port of Aden on Sunday to replenish food and water supplies after a trip from the Mediterranean. On Monday it entered waters off the Somali coast where local pirates have sharply increased hijackings of ships for ransom.
"The Neustrashimy missile frigate has assumed patrol duty to protect Russian shipping," Capt 1st Rank Igor Dygalo said.
Somali pirates have seized around 60 ships so far this year off the coast of the east African nation, which has no effective government and no navy to police its coastline.
At the beginning of June, the UN Security Council passed a resolution permitting countries to enter Somalia's territorial waters to combat "acts of piracy and armed robbery at sea."
"In order to ensure safety of Russian ships the Neustrashimy will use all means and measures sanctioned by the UN Security Council," Dygalo said.
He also said the Russian warship may join, if necessary, an international naval group fighting piracy in the region.
U.S. warships from the 5th Fleet are currently surrounding a Ukrainian ship, the MV Faina, that was seized by Somali pirates on September 25. The Faina, which was carrying 33 T-72 tanks and other heavy weaponry, has a crew of 17 Ukrainian nationals, two Russians, and one Lithuanian on board.
The Faina's Russian captain died of a heart attack after the vessel was seized. The pirates holding the ship have demanded an $8 million ransom, and have threatened to kill the hostages if a military operation is launched against them.
NATO and the EU have announced plans to increase by the end of the year their naval presence in the Gulf of Aden, which is one of the world's busiest and most dangerous shipping lanes with about 20,000 ships passing through the area annually.