A Chinese fisherman died Tuesday after being hit by a rubber bullet during a raid by South Korean coast guard commandos on illegal fishing in the Yellow Sea, officials said.

The 44-year-old was declared dead around 6pm (0900 GMT), hours after he was rushed by helicopter to a hospital in the southwestern port of Mokpo, a coast guard spokesman told AFP.

"We believe a rubber bullet hit his chest during a raid by coast guard commandos to stop illegal fishing," he said.

Some 30 Chinese boats were illegally fishing in South Korean waters near Hongdo island when a 3,000-tonne coast guard ship launched the operation, he said.

"Coast guard officers used rubber bullets to control the Chinese sailors who brandished knives and other deadly weapons," the spokesman said, adding two boats with an unknown number of crew were seized.

The Chinese embassy in Seoul conveyed its "strong dissatisfaction" to South Korea over the incident, China's state media reported.

China has asked South Korea to investigate the case and ensure such incidents are not repeated, Xinhua said.

Illegal fishing by Chinese boats is common in South Korean waters, with hundreds of craft seized every year.

Chinese sailors have often wielded weapons to resist arrest and coast guard officers have used tear gas and rubber bullets to subdue them.

In September 2008 a South Korean drowned while trying to inspect a Chinese boat.

In December 2010 a Chinese boat overturned and sank in the Yellow Sea after ramming a South Korean coast guard vessel. Two Chinese crewmen were killed.

Last December a South Korean coast guard officer was stabbed to death in a struggle with Chinese sailors.