Kenya ? The U.S. military has stepped up activities in the pirate-infested waters off Somalia, going to the aid of hijacked cargo ships twice this week. American medics treated wounded North Korean sailors on one vessel, and the Navy was tracking another after destroying two pirate skiffs lashed alongside.

The U.S. military acted on tips and distress calls to help two cargo ships hijacked since Sunday, including the North Korean vessel whose 22-member crew fought off the pirates in a bloody battle. At least one pirate died and three North Koreans were wounded.

U.S. sailors boarded the Dai Hong Dan on Tuesday at its invitation to treat the injured.

The Navy is considering increasing patrols in the shipping lanes off Somalia, perhaps trying to set up “sting” operations using commando ships posing as merchant vessels to draw pirates.

The United States also has supported efforts to quell an Islamic insurgency in Somalia.