Beijing claims Taiwan as part of its territory, and has refused to rule out using force to bring the island under its control.

The May 20 inauguration of incoming president Lai Ching-te will be closely watched globally, as Beijing said prior to the January vote that Lai's election would bring "war and decline" to Taiwan.

The Taiwan Military News Agency said Friday that Taipei's air force had conducted routine training exercises for its jet pilots "to enhance precision strike capabilities in aerial combat", without specifying when.

Fighter jets were equipped with US-made Maverick missiles and laser-guided bombs to hit "sea and land targets at the offshore reef range near Penghu," the agency said on its website, referring to a small collection of islands administered by Taiwan.

Footage released by the agency showed personnel loading the projectiles -- which had "US Air Force" displayed on them -- under the wings of the jets.

A pilot then released the missiles from the fighter jet, and the video footage showed an explosion in the waters around Penghu.

Like Lai, Taiwan's current President Tsai Ing-wen rejects Beijing's claim over the island.

Since she took power in 2016, her administration has boosted economic and military ties with the United States, a key partner for Taiwan and a major weapons provider.

On May 20, her deputy Lai will assume the reins of Taiwan's presidency amid sky-high tensions between Taipei and Beijing, which maintains a military presence around Taiwan with warships, drones and planes.

Beijing has stepped up patrols in recent months around Taiwan's outlying Kinmen islands -- which are administered by Taipei but located just five kilometres (three miles) from the Chinese city of Xiamen.

On Thursday, Taipei's coast guard sounded the alarm over a fleet of seven Chinese official ships and five coast guard ships around Kinmen, with 11 of them entering restricted waters for about 90 minutes before sailing away.

Thursday's show of maritime force was "the fourth formation of Chinese coast guard ships sailing in Kinmen waters" in May, it said.