A United States warship collided with a South Korean fishing vessel in the East Sea on Tuesday, while conducting a joint military drill, the two countries’ militaries said.

US cruiser USS Lake Champlain clashed with South Korean fishing ship 502 Namyang about 83 kilometers south of Ulleung Island at around noon, according to South Korea’s military. US-led Combined Forces Command also confirmed the incident. 

There were no casualties and the exact cause of the incident has not yet been ascertained, according to the two countries’ militaries. The fishing boat, who reportedly carried six crew members, is on its way to return to a port at Guryongpo, North Gyeongsang Province, said the CFC.

“It is quite unusual for a military ship to collide with a fishing vessel. Once the fishing ship returns to port, we will conduct an investigation to find out exactly what happened,” said an official from the Ministry of Public Safety Service.

South Korea and the US have been engaging in a joint naval exercise since April 29 as a show of force against North Korea’s nuclear and missile threats.

Joining the exercise are US Navy strike group led by USS nuclear-powered Carl vison aircraft carrier. Guided missile destroyers USS Wayne E. Meyer, USS Michael Murphy and guided missile cruiser USS Lake Champlain are also participating the drill.

By Yeo Jun-suk (jasonyeo@heraldcorp.com)