TAIPEI (REUTERS) - Taiwan's air force scrambled on Friday (Oct 1) to warn away 25 Chinese aircraft that entered its air defence zone, the defence ministry in Taipei said, the same day that China marked its national day, the founding of the People's Republic of China.

Taiwan - which China regards as a renegade province - has complained for a year or more of repeated missions by China's air force near the island, often in the south-western part of its air defence zone close to the Taiwan-controlled Pratas Islands.

The latest Chinese mission involved 18 J-16 and four Su-30 fighters plus two nuclear-capable H-6 bombers and an anti-submarine aircraft, the Taiwan ministry said.

It said Taiwan sent combat aircraft to warn away the Chinese aircraft, while missile systems were deployed to monitor them.

The Chinese aircraft all flew in an area close to the Pratas, with the two bombers flying closest to the atoll, according to a map that the ministry issued.

The largest incursion to date happened in June, involving 28 Chinese air force aircraft.

China's latest mission came less than a day after its government launched a vituperative attack on Taiwan's foreign minister, evoking the words of revolutionary leader Mao Zedong to denounce him as a "shrilling" fly for his efforts to promote Taiwan internationally.

Taiwan Foreign Minister Joseph Wu, a fluent English speaker, is an outspoken supporter of the island's efforts to push back against pressure from China and regularly appears on think-tank and other panels.

In a lengthy denunciation of Mr Wu late on Thursday, China's Cabinet-level Taiwan Affairs Office said he was a "diehard" supporter of Taiwan independence who peddled lies that Taiwan is a sovereign country.

It quoted a poem written by Mao in 1963, The River All Red, which was a denunciation of the Soviet Union and United States.

"All forms of comments on Taiwan independence are but flies 'humming, with a burst of shrilling and a fit of sobbing'," China's Taiwan Affairs Office said.

Taiwan's foreign ministry said the attack was "not worthy" of comment.

However, Taiwan's Cabinet-level Mainland Affairs Council, which crafts policy on China, condemned it as "slander and abuse".

"This kind of verbal violence, unprecedented in the international community, only highlights the overstepping of the rules of the Taiwan-related body on the other side of the Taiwan Strait and how far away it is from civilised society," it said.

China has stepped up military and political pressure to try and force Taiwan to accept Chinese sovereignty.