Taiwan says government sites are on constant guard for attack

Major government websites and those belonging to associates of President Chen Shui-bien - who Beijing sees as a supporter of Taiwanese independence - are thought to be among the principal targets.

China views Taiwan as a renegade province and has repeatedly said it will use force to prevent the island declaring itself independent from the mainland.

Tuesday's national day, known as the 'double tenth', is the first to be celebrated since this year's landmark general elections which saw an end to five decades of rule by the Kuomintang nationalist party.

Earlier this year, several government sites were vandalised by mainland hackers following President Chen's inauguration on 20 May.

Flag waving

In retaliation, Taiwanese hackers returned fire at the mainland, plastering the homepage of China's railway ministry with pictures of the Taiwanese flag and the Taiwanese national anthem.

Officials say China may want to embarass Taiwan's leaders on National Day

However, this time Taiwanese authorities say they have learnt the lessons of previous attacks and are now on a constant state of alert for signs of interference.

"We have done everything necessary to be prepared," said Tsai Ing-wen, chairwoman of the island's Mainland Affairs Council.

"The factors have been taken into consideration when we implemented national security measures,'' she said.

In August last year, hackers on both sides of the Taiwanese Straits engaged each other in a fierce cyberwar after the then Taiwan President, Lee Teng-hui, suggested Taiwan's relationship with Beijing be conducted on "state-to-state" lines.

The statement incensed China, which saw it as a claim for independent status.

One message posted by irate Chinese hackers on Taiwanese government sites read: "Taiwan is an inalienable part of Chinese territory and will always be. The Taiwan Government headed by President Lee cannot deny it. Only one China exists and only one China is needed.''