South Korean navy personnel secure a boat after seizing it from the pirates [REUTERS]

South Korea's navy has rescued all crew members aboard a South Korean chemical ship hijacked by
Somali pirates in the Arabian Sea, President Lee Myung-bak said.

Navy commandos stormed the hijacked vessel on Friday, killing eight pirates and capturing five during the rescue mission, military officials said at a separate briefing.

"Our soldiers rescued all of 21 crew aboard Samho Jewelry, including eight Koreans, who were hijacked by Somalia pirates," President Lee told reporters.

The vessel, en route to Sri Lanka from the United Arab Emirates, was seized at the weekend. Aboard was a crew of eight Koreans, 11 Myanmar nationals and two Indonesians.

All were rescued alive, although a South Korean skipper of the chemical freighter suffered a non-critical gunshot wound to his stomach during the raid.

Firefight

The firefight left several pirates missing and believed killed although their bodies have not been found, spokesmen said. Three South Korean commandos were slightly hurt.

Seoul ordered a destroyer on patrol in the Gulf of Aden to give chase after reports of the vessel being hijacked. President Lee ordered "all possible measures" to save the crew.

Commando's chased the hijacked ship for days, and started a rescue attempt before dawn on Friday. The mission lasted five hours.

This hijacking came two months after an oil supertanker belonging to the same firm was freed after seven months in captivity, the government and local media said.

The pirates said they had received a record ransom of $9.5m for the release of the supertanker.

According to the London-based International Maritime Bureau, which monitors maritime crime, there have already been 22 incidents reported off the coast of Somalia in 2011, including four hijackings.

Currently, 31 vessels are being held by Somali pirates, the Bureau reported.