Five Chinese coast guard ships sailed through Taiwan's "restricted waters" for three hours on Tuesday before they were expelled, Taiwanese coast guard said.

The incident comes less than a week before Taiwan holds an inauguration for its incoming president Lai Ching-te, who China regards as a "dangerous separatist".

China claims Taiwan, a self-ruled democracy, as part of its territory and has said it would not renounce the use of force to bring it under Beijing's control.

In recent months leading up to the May 20 inauguration, Chinese coast guard ships have made frequent appearances around the waters of Kinmen, an island administered by Taipei located five kilometres (three miles) from the Chinese city of Xiamen.

On Tuesday, the branch of Taiwan's coast guard that patrols Kinmen, Matsu and Penghu -- all outlying islands -- said that five Chinese ships had "gathered in waters south of Kinmen and crossed the border to enter our waters" at 3 pm local time (0700 GMT).

"The coast guard... quickly dispatched patrol ships to respond and firmly enforced the law," they said in a statement.

"Under our strong enforcement, the Chinese coast guard ship sailed out of the country's restricted waters at 5:09 pm."

It added that Tuesday's incident was the fifth formation of Chinese coast guard ships entering Kinmen's waters in May.

Last week, Taiwanese coastguard said a dozen Chinese ships were around Kinmen -- with 11 of them entering Taiwan's "restricted" waters -- but left after 90 minutes.

Taiwan's coast guard said these recent actions "seriously affect navigation safety and undermine peace and stability across the Taiwan Strait".

"We urge the Chinese side to exercise self-restraint and immediately cease this irrational behaviour," it said.

Beijing maintains a near-daily military presence around Taiwan, sending in warplanes and naval vessels as it ramps up pressures against the current administration of outgoing President Tsai Ing-wen, who rejects China's claim on the island.

On Tuesday evening at around 7 pm, Taipei's ministry of defence said it had detected 23 Chinese aircraft around the island since 5 pm, including fighter jets and drones.

Fifteen of the aircraft crossed the median line bisecting the Taiwan Strait, a narrow 180-kilometre (110-mile) waterway separating the island from China.

China had said Lai, currently Tsai's deputy who has vowed to maintain her position in terms of defending the island's sovereignty, would bring "war and decline" to Taiwan.

Tensions around Taiwan and the nearby hotspot region of South China Sea -- which Beijing claims nearly its entirety of -- have been sky-high as Lai's inauguration nears.