A South Korean cargo ship carrying oil exploded in waters off the country's northwestern port city of Incheon earlier Sunday, killing three crew members and leaving eight others missing, local media reported.

The accident occurred three miles north of Jawol Island near Incheon at around 8:05 a.m. local time, shortly after the cargo ship left the port, the Coast Guard was quoted by Seoul's Yonhap News Agency as saying.

A total of 16 crew members were on aboard the 4191-ton freight, including five South Koreans and 11 Burmese.Three of them were killed on the spot and eight others went missing. Five crew members were rescued, reports said.

The Coast Guard has sent a patrol ship to the scene to search for the missing crew. The exact cause of the explosion remains unknown.