A standoff between the Japanese and South Korean coast guards ended peacefully after a joint investigation found that a Korean fishing boat did not violate Japanese waters, an official said Saturday.

The incident began when the 134-ton fishing boat sent an emergency radio message to South Korea's coast guard saying it was being chased by Japanese patrol vessels.

The coast guard dispatched five patrol boats and a helicopter to protect the fishing vessel, which was located 44 nautical miles (50 miles) off Tongyoung, about 300 miles south of Seoul.

Around 10 minutes later, four Japanese coast guard boats arrived and accused the fishing boat of intruding into Japanese waters.

A joint check found that the fishing boat had been in South Korean waters, said Han Kap-hun, an officer from the country's coast guard.

The six-hour confrontation ended late Friday (1120 GMT) when the four Japanese patrol vessels withdrew.