A freighter registered in Cambodia caught fire at a port in Japan's northern prefecture of Hokkaido early Thursday, leaving six Russian crew members missing, local media reported.

Local rescuers, including firefighters and Japanese Coast Guard, reached the accident site after they received an emergency call at around 1:45 a.m. local time, Japan's Kyodo News Agency cited local authorities as saying.

Three Russian sailors, among a total of 18 crew members, were rescued and have been sent to hospital without serious injuries, according to the report.

Rescuers will search for the missing sailors after the fire is controlled, said Kyodo.

The 497-ton crab freighter docked at the port Tuesday with 14 Russian and four Ukrainian crew members on board.