MOGADISHU, Somalia—Russian and British forces repelled a pirate attack on a cargo ship in the first action by a Russian warship sent to fight hijackings off Somalia, the two nations said Wednesday.

Russian Navy spokesman Capt. Igor Dygalo said the Russian missile frigate Neustrashimy and the British frigate Cumberland each sent up a helicopter and foiled pirates trying to take over the Danish vessel.

“The pirates tried to hit the ship with automatic weapons fire and made several attempts to seize it,” Dygalo said on state-run Vesti-24 television.

He did not say whether the Russians or British opened fire.

The British Ministry of Defense said that the incident occurred Tuesday and one of its warships had boarded a foreign-flagged dhow—a traditional wooden vessel—suspected of piracy.

Russia sent the Neustrashimy, or Intrepid, to protect Russian ships and crew off Somalia’s coast after a Ukrainian freighter with three Russians aboard was hijacked in September.

Attacks have continued virtually unabated off Somalia, which has had no functioning government since 1991.

Turkish maritime officials said that pirates had commandeered the Karagol, a Turkish tanker bound for India, on Wednesday, 16 miles (26 kilometers) off the coast of Yemen. It was carrying 4,500 tons of chemicals and 14 Turkish personnel.

The total number of naval attacks off Somalia stood at 83 before the Karagol was seized, with 33 ships hijacked and 12 still in pirates’ hands, most notably the Ukrainian freighter.

The U.N. Security Council unanimously adopted a resolution in June allowing ships of foreign nations that cooperate with the Somali government to enter their territorial waters “for the purpose of repressing acts of piracy and armed robbery at sea.” About 20,000 ships sail through the Gulf of Aden each year, compared to 13,000 that pass through the Panama Canal and 50,000 that traverse the Straits of Malacca—formerly the most pirate-infested waterway in the world.