TAIPEI (Reuters) -Taiwan's military sent forces to keep watch on Thursday after a Chinese naval formation led by the aircraft carrier Shandong passed the island's south and entered the western Pacific, Taiwan's defence ministry said.
The Shandong participated in Chinese military drills around Taiwan in April, operating in the western Pacific. It also sailed through the Taiwan Strait in June and last month also carried out drills in the western Pacific.
The ministry said in a statement the formation led by the Shandong had "crossed the Bashi Channel and entered the western Pacific", though it did not say how many ships there were.
The military has deployed "appropriate" forces to keep watch the ministry added, without elaborating.
Earlier on Thursday, the ministry said it had detected 15 Chinese military aircraft which entered Taiwan's air defence zone, referring to a broader area of air space Taiwan monitors rather than its territorial air space.
The aircraft, which it said included H-6 bombers, J-16 fighters and drones, were accompanying Chinese warships carrying out "joint combat readiness patrols", the ministry said.
China's defence ministry did not answer telephone calls seeking comment outside of office hours.
China, which has never renounced the use of force to bring Taiwan under its control, has stepped up military activity near the democratically governed island, responding to what it calls "collusion" between Taiwan and the United States.
Taiwan disputes Beijing's sovereignty claims.