Taiwan's defence ministry warned on Tuesday of a possible "sharp increase" in military tensions after reporting renewed Chinese military activity including fighter jets crossing the sensitive median line of the Taiwan Strait.
Democratically governed Taiwan, which China claims as its own territory, has complained for three years of increased military pressure from Beijing, mostly in the form of China's air force flying near the island.
The ministry said that on Tuesday morning it spotted 12 Chinese military aircraft in its air defence identification zone, of which seven crossed the median line - six J-10 fighters and a single drone.
Five Chinese ships also carried out "combat readiness patrols", the ministry said, without giving a location.
The median line had for years served as an unofficial barrier between the two sides, until China's air force began regularly crossing it a year ago.
"The continued military harassment by the Communist military in the region may lead to a sharp increase in tensions and worsen regional security," the ministry said, calling on Beijing to "immediately stop such unilateral acts".
Maintaining the peaceful and stable status quo in the Taiwan Strait is critical to the security and prosperity of the Indo-Pacific region, and all parties, including Beijing, have a common responsibility to uphold it, the ministry added.
The latest Chinese mission happened the same day Taipei Mayor Chiang Wan-an, from Taiwan's main opposition party the Kuomintang which traditionally favours close relations with Beijing, arrived in Shanghai for annual city-to-city talks.
