TAIPEI, Aug 29 (Reuters) - 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.
His office said the city government has many times reiterated that "the more difficult the environment is, the more the two sides should communicate".
"What the people of Taiwan want is peace and prosperity. This is the voice of the people and the firm position of the city government," it said.
Speaking to reporters before leaving for Shanghai, Chiang said the city forum was a good way to keep communication channels open and send a message of "peaceful values".
Taipei city councillors for Taiwan's governing Democratic Progressive Party issued a joint statement saying Chiang should "speak for the Taiwanese people" and demand an end to China's military activities.
