Taiwan on Monday called on China to stop its “destructive unilateral actions” after more than 100 Chinese fighter jets and nine navy ships were detected in areas around the autonomous island.

Beijing continues to claim the island of Taiwan as its own territory that will one day be captured, by force if necessary, and has increased diplomatic and military pressure on Taipei in recent years.

Taiwan’s Defense Ministry described the number of fighter jets detected in 24 hours as a “recent high”, while Beijing has so far refrained from issuing any official comment on the raids.

“Between the morning of September 17 to 18, the Ministry of National Defense detected a total of 103 Chinese aircraft, which represents a recent high and has posed serious challenges to security across the Taiwan Strait and in the region,” he says in a statement.

Beijing’s “continued military harassment can easily lead to a sharp escalation of tension and worsen regional security,” the ministry said while calling on China to “immediately stop such destructive unilateral actions.”

Of the total combat aircraft detected, 40 crossed the so-called median line of the Taiwan Strait that separates the island from China and entered its southwest and southeast air defense identification zone (ADIZ), the statement said.

Last week, Taipei also reported increased incursions by Chinese fighter jets and ships.

The surge came as Beijing said its troops were on “high alert” after two ships belonging to the United States and Canada sailed through the Taiwan Strait.

Taiwan’s Defense Ministry said 68 Chinese aircraft and 10 warships were detected around the island between Wednesday and Thursday morning.

The ministry said some of those planes and warships were headed to an unspecified area of the Western Pacific to “conduct joint maritime and air training” with China’s Shandong aircraft carrier.

Taipei officials said that the Shandong, one of two operational aircraft carriers in the Chinese fleet, was detected last week about 60 nautical miles (110 kilometers) southeast of Taiwan heading into the Western Pacific.

Japan’s Defense Ministry also said last week that its navy had detected six ships – including frigates, destroyers, a fast combat support ship and the Shandong – sailing in waters about 650 kilometers (400 miles) south of Miyakojima Island, east of Taiwan.

He confirmed that planes and helicopters had been detected taking off and landing from Shandong, although China has not officially commented on any drills taking place in the Western Pacific.

Analysts said China could be flexing its muscles to counter US influence in the Asia-Pacific, as it leads multiple rounds of military exercises with allies across the region.

“Politically, China aims to counter the military containment of democratic allies led by the United States,” Su Tzu-Yun, an analyst at Taiwan’s National Defense and Security Research Institute, told AFP.

Following the visit of Nancy Pelosi, then speaker of the US House of Representatives, to Taipei last August, China organized the largest war exercises in its history in Taiwan.

Then, in April this year, Beijing held a three-day “Joint Sword” military exercise to simulate the encirclement of the island after Taiwan President Tsai Ing-wen met with the president of the United States House of Representatives, Kevin McCarthy, in California.

While Beijing has yet to issue any statement on its latest incursions, the Chinese state-run tabloid Global Times posted a comment on the social media platform Weibo.

“The mainland and Taiwan belong to the same China, and Taiwan is a sacred and inalienable part of China,” reiterating Beijing’s long-standing policy.

“The relevant combat training activities of the People’s Liberation Army are necessary actions to safeguard national sovereignty and territorial integrity,” he added, referring to China’s military.