Flotillas attached to the Beihai, Donghai and Nanhai Fleets proceeded with exercises in the west Pacific on Sunday despite foreign disturbance, according to the People's Liberation Army.

Foreign military vessels and reconnaissance aircraft remained in the exercise area for an undue time monitoring Chinese activity in the close distance and seriously disturbing the naval drill.

On Saturday, Defense Ministry spokesman Geng Yansheng told a press briefing that Japanese authorities notified China on Oct 23 that a Japanese fishing boat had sent a distress signal from a prohibited area at the site of the drill.

China allowed Japanese vessels to enter the area to facilitate the rescue out of humanitarian concern, Geng said.

Chinese authorities had previously publicized the exercise areas via international maritime organizations in accordance with international practice, alerting foreign vessels and planes to take precautions.

The drill is the first open-sea drill in which maritime and air forces from all three of China's fleets have taken part.

Participating teams had been heading for destinations since Oct 18 and started a confrontation drill in the west Pacific on Oct 25.