Police in Hokkaido said Saturday that three members of a North Korean fishing boat have been arrested on suspicion of plundering a remote fishing hut.

On Friday the crew cut ropes tethering their wooden boat to a Japan Coast Guard vessel near Hakodate port and tried to flee, but the vessel was recaptured later that day.

The boat had been impounded on Nov. 30, two days after being spotted washed ashore on an uninhabited island off the town of Matsumae. The police have been questioning the 10 crew members.

The three were arrested on suspicion of stealing a power generator that was found on their boat, police sources said.

The Immigration Bureau has taken custody of six other members and the remaining one has been hospitalized after complaining of ill health.

The police believe the crew also caused damage to and stole other property, such as appliances, from a fishing hut on the island. Another generator and a boiler were found destroyed.

The damage is estimated at ¥8 million, according to the fishery cooperative in Matsumae that owns the hut.

The fishermen told coast guard officials that they left the port of Chongjin in northeastern North Korea in September to go squid fishing in the Sea of Japan before their steering wheel failed about a month ago.

Chief Cabinet Secretary Yoshihide Suga said Saturday that the police, the coast guard and the Self-Defense Forces will work together in dealing with the recent increase in North Korean boats arriving along the coast.

The boats, some in distress, some abandoned and some with dead bodies on board, have raised fears about infiltration by spies as tensions with North Korea surge over its missile and nuclear weapons programs. North Korea has test-fired two missiles over Japan and threatened to destroy its old wartime foe.

Most experts say the wooden boats are just carrying fishermen including soldiers drafted to fish. There has been no suggestion the crew are defectors.