U.S. sailors brought injured North Koreans aboard their destroyer for medical treatment after the Koreans were shot and wounded in a battle with pirates off the coast of Somalia, the Navy said Wednesday.

The destroyer USS James E. Williams assisted Korean sailors who retook control of their North Korean-flagged vessel Tuesday in a deadly battle with Somali pirates who had hijacked the boat late Monday.

Lt. John Gay, deputy spokesman for the U.S. 5th Fleet in Bahrain, told The Associated Press that pirate attacks are not rare in U.S. Navy's area of operations and that "it's our duty to help all vessels in distress."

According to the military, the North Koreans asked for medical assistance and gave permission for U.S. Navy personnel to board the ship.

When the Navy boarded the ship with a small team of medics, security personnel and an interpreter, the Koreans already had regained control of the vessel and detained all pirates, the Navy said.

One pirate was dead and three were wounded, while three Korean sailors also were wounded, the Navy said. The Navy medics treated all six for gunshot wounds. The Korean sailors were taken aboard the American destroyer and treated there for two hours. They were returned to the Korean ship the same night.

The pirates remain detained on the Korean vessel, the U.S. Navy said.

On Tuesday, a helicopter flew from the 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, the military said.

Defense Department spokesman Geoff Morrell said the incident didn't indicate the U.S. military was taking a more aggressive stance toward pirates off Somalia, but added that piracy in the Horn of Africa region is a concern because "you're talking about an area that has seen greater terrorist involvement."

Morrell said it was logical that the military would want to know "what is being transported on the high seas and who is out there operating and if they have nothing but the best intentions in mind."

A Navy spokeswoman, Lt. Jessica Gandy, said later that the American destroyer had not been shadowing the North Korean ship. She said it was not known what its cargo was.

The attackers were believed to have been security guards hired by a local ship agent, said Andrew Mwangura, program coordinator of the Seafarers Assistance Program, which independently monitors piracy in the region.

An international watchdog reported this month that pirate attacks worldwide jumped 14 percent in the first nine months of 2007, with the biggest increases in the poorly policed waters of Somalia and Nigeria.

Reported attacks in Somali waters rose to 26, up from eight a year earlier, the London-based International Maritime Bureau said through its piracy reporting center in Kuala Lumpur, Malaysia.

This is the third time Somali gunmen have been overpowered by mariners.

In 1989, crew members of the MV Alpha Mitchel managed to overpower their captors in Somalia waters. In 2004, six crew members of the MT Jenlil also managed to escape to Yemen after overpowering their captors in Somalia territorial waters.

The U.S. 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.

Cmdr. Lydia Robertson, the 5th Fleet spokesman, said coalition ships fired on and sank two pirate skiffs tied to the Golden Nori. A Navy photo showed one of the skiffs burning after being hit by a gun aboard the USS Porter, a guided-missile destroyer.

Robertson could not confirm CNN reports Tuesday that the Japanese tanker was filled with highly flammable benzene. But she said, "we were aware of what was on the (Golden Nori) ship when we fired."

CNN said the USS Arleigh Burke, another guided-missile destroyer, also was involved in the operation and had entered Somali waters with the approval of the government. Robertson said she could not confirm the report because the operation was continuing.

Somalia has had 16 years of violence and anarchy and is now led by a government battling to establish authority even in the capital. Its coasts are virtually unpoliced.

Piracy off Somalia increased this year after Ethiopian forces backing Somali government troops ousted an Islamic militia in December, said Mwangura at the Seafarers Assistance Program.

During the six months that the Council of Islamic Courts ruled most of southern Somalia, where Somali pirates are based, piracy abated, Mwangura said.

At one point, the Islamic group said it was sending dozens of fighters to crack down on pirates. Islamic fighters stormed a hijacked, United Arab Emirates-registered ship and recaptured it after a gunbattle in which pirates — but no crew members — were reportedly wounded.