TOKYO (AFP) - Japan has lodged a protest with Pyongyang after one of its patrol vessels was chased by an apparently armed fishing boat believed to be from North Korea, the government said Thursday (July 13).

The incident occurred Friday in the Sea of Japan (East Sea) and within Japan's exclusive economic zone (EEZ), which extends 200 nautical miles from the coast, Tokyo said.

The fisheries agency ship was on patrol when it was pursued by "a vessel of unknown origin which had what appeared to be a gun", top government spokesman Yoshihide Suga told reporters.

"The patrol ship suffered no damage as it urgently left the area for safety," Suga said.

"Given the high possibility that the vessel is linked to North Korea, we have lodged a strong protest through the embassies in Beijing," said Suga, who noted Japan had observed the ship's crew and collected other information.

Japan and North Korea do not have diplomatic relations but Tokyo sometimes makes diplomatic protests to Pyongyang by having its embassy in the Chinese capital contact North Korea's.

Japan's Sankei Shimbun newspaper, quoting fisheries agency sources, said the North Korean ship pointed the gun at the Japanese vessel.

Suga withheld comment on what the ship was doing in the waters.

News reports, however, said the incident took place near a squid-fishing area where North Korean ships often operate.