A Chinese envoy on Monday toured a southern Taiwan city, in a rare visit by a top mainland official to the area known for its vehement anti-China sentiment, officials said.

Zheng Lizhong, China's second-ranking envoy to Taiwan, visited the city of Tainan at the invitation of the island's ruling Kuomintang party and did not face any protests despite concerns about his safety, they said.

"The purpose of the visit is to explore more economic and trade opportunities between the two sides," Zheng, vice president of China's quasi-official Association for Relations Across the Taiwan Strait, told reporters.

He visited an orchid farm and met with a group of farmers in Tainan -- the stronghold of the China-sceptic opposition Democratic Progressive Party (DPP).

Zhang Mingqing, another Chinese official, was pushed to the ground by a crowd led by a DPP politician when he visited the city in October 2008.

The incident was caught on camera and triggered fury in Beijing, with the Chinese government calling for "severe punishment" of those found guilty.

The DPP politician later received a four-month jail sentence for assault from a district court there.

Zheng's association is authorised by Beijing to handle civilian exchanges with Taiwan in the absence of official contacts between the two sides.

Beijing still regards Taiwan as part of its territory awaiting reunification, by force if necessary, even though the island has ruled itself for more than 60 years since its split with the mainland in 1949 at the end of a civil war.

But ties between Taipei and Beijing have improved markedly since Ma Ying-jeou of the China-friendly Kuomintang party came to power in 2008 on promises of beefing up trade links with China and allowing more Chinese tourists to visit.

Ma was re-elected to a second and the last four-year term in last month's elections.