Seoul, South Korea (CNN) -- Four South Korean coast guard personnel were wounded Monday while trying to apprehend Chinese sailors in Korean waters, a coast guard official said.
The coast guard tried to stop the Chinese ship on suspicion of illegal fishing in the Yellow Sea, but the sailors attempted to escape, said the official, who gave only his last name of Kim.
The coast guard personnel managed to board the ship after pursuing it for 2 kilometers, Kim said, but they were attacked by the Chinese sailors wielding knives, hooks and a sickle.
One was cut in the head, two others sustained minor injuries and a fourth jumped overboard to evade attack. He was later picked up safely. The four are being treated in a hospital in Mokpo in the southwest of the country, Kim said.
Nine Chinese sailors were arrested and are being questioned by Korean maritime police.
Officials at the Chinese Ministry of Foreign Affairs were not immediately available for comment Monday, which is a public holiday in China.
Earlier this month, a South Korean court sentenced the captain of a Chinese fishing boat to 30 years in prison for murdering a South Korean coast guard officer during a confrontation in the Yellow Sea last year.
The court in the port of Incheon also handed down prison terms to several other crew members of the Chinese vessel, which the South Korean coast guard officials boarded on December 12 because they suspected it of fishing illegally.
The Yellow Sea, which contains important fishing and crab grounds, has been a point of contention for several Asian countries, most notably North and South Korea, who have long disagreed on whose waters end where.
The South Korean coast guard stopped hundreds of Chinese boats last year on suspicion of illegal fishing in the sea. Disputes over fishing rights have resulted in dozens of boat seizures.
CNN's Chi-Chi Zhang and journalist Jungeun Kim contributed to this report.