TOKYO, Feb. 9 (Xinhua) -- A Japanese Maritime Self-Defense Force submarine collided with a commercial vessel on Monday in the Pacific Ocean off the western main island of Shikoku, slightly injuring three crew members on the submarine, government officials said.
In the incident, the 84-meter-long Soryu scraped the hull of the vessel when it was surfacing, the Defense Ministry said.
Top government spokesman Katsunobu Kato said at a press conference that the clash occurred at around 10:58 a.m. local time (0158 GMT) off Cape Ashizuri in Shikoku's Kochi Prefecture.
When contacted by Japan's Coast Guard, crew on the commercial ship said they did not feel the impact and the vessel did not appear to have sustained any damage, Kato added.
According to Coast Guard officials, the ship was from China's Hong Kong with a displacement of about 50,000 tons. The submarine's antenna mast and other upper parts were slightly damaged but it was able to continue sailing.
Defense Minister Nobuo Kishi said the submarine was carrying out routine training when it saw the commercial vessel through its periscope but was unable to avoid it in time.
As the submarine's communications equipment was damaged in the collision, there was an hours-long delay in reporting the incident by mobile phone, he added.
The Japan Transport Safety Board said it has started a probe into the accident.
