A South Korean coastguard has been killed and another injured when they were stabbed by a Chinese captain whose boat was stopped for suspected illegal fishing.
Two Chinese boats were stopped in South Korea's Yellow Sea waters rich in blue crabs, anchovies and croaker, but details of the fight were unclear.
Coastguard officials, who declined to be named, said the captain of one of the boats stabbed the South Korean officers.
The officers were taken to a hospital in the port city of Incheon. Nine Chinese fishermen were in custody, the coastguard said.
A South Korean officer who was stabbed in the side died, but the other officer was not seriously hurt, the officials said. There was no immediate comment from the Chinese Foreign Ministry.
The coastguard said it had seized about 430 Chinese ships for illegal fishing in the Yellow Sea this year, up from 370 last year. The ships are usually released after a fine is paid, though violence occasionally occurs.
Chinese fishing fleets have been going further afield to feed growing domestic demand for seafood. In 2008 a South Korean coastguard was killed and six others injured in a fight with Chinese fishermen in South Korean waters.
The fight happened after officers from two coastguard vessels boarded the fishing boat to arrest the nine fisherman, coastguard spokesman Kim Dong-jin said.
The Chinese captain resisted by wielding an unidentified weapon, Mr Kim said. The injured officer was undergoing surgery and the Chinese captain had minor injuries, he added.
South Korea's Foreign Ministry summoned China's ambassador in Seoul and lodged a strong protest, South Korea's Yonhap news agency reported.