South Korean President Lee Myung-bak called for "strong" measures to protect the country's coast guard sailors during the crackdown on illegal fishing by Chinese boats.

This could mean more equipment and personnel are allocated to the coast guard service so there is no repeat of the fatal attack on two sailors during a raid on a Chinese boat suspected of fishing illegally in South Korean waters.

Coast Guard officer Lee Cheong-ho, 41, was allegedly stabbed by the captain of the Chinese fishing boat and died shortly after in hospital. Another coast guard member was stabbed but his condition isn't life-threatening, a report by the South Korean news agency Yonhap said.

The confrontation between the coast guard and Chinese fishing vessel was one of the most difficult in years, said the team that boarded the ship, a report in Joongang Daily said.

"It was the strongest resistance ever," Kang Hee-soo, a member of the SWAT team involved in the boarding, said. "I think our government needs to handle illegal fishing more decisively. We need to expand the number of officers and must not hesitate to use firearms if the resistance is violent in order to stop more Korean deaths from happening."

"When the team approached the vessel, the Chinese resisted aggressively, throwing empty beer bottles and fishing gear," Park Seong-gu, another SWAT team member, said. "When we got onto the vessel, the Chinese sailors became more aggressive, started using bamboo spears and long shovels, which seemed to be refurbished for attacking."

China formally apologized for the affair after its ambassador was summoned by the South Korean government. Chinese Foreign Ministry spokesman Liu Weimin expressed "regret" over the killing, calling it an "unfortunate event," Yonhap reported.

But the incident, which happened this week about 100 miles west of Incheon, South Korea, further bruised relations between Seoul and Beijing, already strained over Chinese activity within what Seoul claims as its territorial waters in the South China Sea.

Lee's spokesman, Park Jeong-ha, said the president wants to establish "fundamental" and "diplomatic" measures to crack down on Chinese vessels that are increasingly poaching in South Korea's exclusive economic maritime zone.

This could mean more ships and officers going on more frequent patrols, Park said.

"The government is calling on the Chinese government to take measures that would be acceptable to our people to prevent such an incident from happening again," Seoul's foreign ministry spokesman Cho Byung-jae said.

Coast guard officials have detained all nine sailors on board the Chinese vessel, including the captain, at Incheon where they are being questioned, Yonhap said.

The Chinese captain could face charges around the killing of the South Korean officer and the eight sailors may face charges of obstructing government officials, the report said.

Yonhap also reported around 300 people gathered outside the Chinese Embassy in Seoul. Protesters threw eggs at the embassy and tried to burn a Chinese flag before minor scuffles with riot police, who broke up the group.

The fishing vessel incident is the latest in a growing number of maritime disputes, mostly territorial, between China and its South China Sea neighbors.

In July, China signed an agreement with the Association of South East Asian Nations to move toward peaceful resolutions of the disputes.

But the deal was notable for its lack of detail, said analysts. Beijing, which is beefing up its maritime patrols, lays claim to many of the South China Sea's large island groupings, even those much closer to the shores of the Philippines, Malaysia, Brunei and Vietnam than China.

The Spratly Islands -- the largest group -- lie off the southwest coast of the Philippines as well as Brunei and Malaysia. Ownership of the Spratly Islands is the most difficult of all the territorial claims because of the number of claimants, including Vietnam and Taiwan.

Further north, off the west coast of the Philippines, lies the Scarborough Shoal, disputed between China and the Philippines. Meanwhile, Vietnam and China are fighting for sovereignty over the Paracels, a group of islands south of China's Hainan Island province and off the east coast of Vietnam.