Fifteen Chinese boats were seized for fishing illegally in South Korean waters in an overnight crackdown conducted by a new Seoul ministry in charge of national safety and security, officials said Friday.

The special crackdown was held simultaneously in four areas off the country's west and south coasts, involving 22 medium- and large-sized Navy vessels, the Ministry of Public Safety and Security said.

Some of the captured ships had grates and wire meshes on both sides to prevent South Korean coast guard officials from getting on board, but no violent clashes were reported, according to the officials.

The clampdown came amid reports that poaching by Chinese fishermen is rampant in those waters.

Since mid-October, coast guard officials have carried out intensive clampdowns on illegal fishing, capturing 42 Chinese ships, they said.

Hundreds of Chinese fishermen are arrested each year for illegally crossing into and fishing in South Korea's western and southern waters, often leading to violent clashes with South Korean coast guard officials. 

On Thursday, Prime Minister Chung Hong-won said the government will conduct a stronger crackdown on illegal fishing by Chinese fishermen by better organizing the use of beefed-up forces composed of 3,000-ton Navy ships, a helicopter and commandos.

South Korea formally launched the new safety ministry on Wednesday that took over responsibilities previously shared by multiple state offices, including the Coast Guard, which was disbanded for its inadequate response to April's ferry disaster that claimed more than 300 lives. (Yonhap)