Kenya ? A U.S. Navy destroyer helped sailors who retook control of their vessel Tuesday in a deadly battle with pirates after the North Korean-flagged ship was hijacked in the piracy-plagued waters off Somalia, the American military said.

The Navy also confirmed that other American warships sank two pirate skiffs late Sunday after answering a distress call from a hijacked Japanese chemical tanker and said U.S. ships were still monitoring that vessel.

In Tuesday’s incident, a helicopter flew from the destroyer USS James E. Williams to investigate a phoned-in tip of a hijacked ship and demanded by radio that the pirates give up their weapons, the military said in a statement.

The crew of the Dai Hong Dan then overwhelmed the hijackers, leaving two pirates dead, according to preliminary reports, and five captured, the military said.

Three seriously injured crew members were taken aboard the Williams, the statement said. The captured pirates remained on the Dai Hong Dan, which the crew was returning to the port of Mogadishu, Somalia’s capital.