China, which views democratically governed Taiwan as its own territory, sends its warships and warplanes into the waters and skies around the island on an almost daily basis, to the condemnation of the Taiwanese government.
While Taiwan's defence ministry offers daily updates of the locations of Chinese military aircraft, it only rarely gives details of where Chinese warships are operating, generally only when it detects aircraft carriers, as happened last week.
Late on Monday, the ministry said a Chinese destroyer and a frigate had entered waters to the southwest of the Penghu islands, home to major Taiwanese navy and air bases and close to the Taiwan side of the strait.
Taiwan's military "closely monitored the formation and responded appropriately using naval and air forces", the ministry added, without elaborating.
The ministry showed colour pictures of both ships taken from the air, but did not give an exact location.
China's defence ministry did not immediately respond to a request for comment.
Earlier this month, it said China's regular military activities around Taiwan are "entirely justified and reasonable" and any tensions are the fault of the government in Taipei.
On Tuesday morning, in its daily update of Chinese activities over the past 24 hours, Taiwan's defence ministry said a total of nine Chinese warships were operating around the island, with 22 military aircraft detected.
While it showed a map of where the Chinese aircraft were, mostly in the strait and to the north and southwest of Taiwan, it did not provide any other information about the location of the warships.
Taiwan's government rejects Beijing's sovereignty claims, saying only the island's people can decide their future.
