Taiwan is preparing to launch a fourth cyberwar unit, a local newspaper reported Wednesday, in response to what it claims is a growing security threat from Chinese hackers.

The new unit is scheduled to open on July 1 and will work to counter cyber attacks on government websites, said the Taipei-based newspaper United Evening News.

It will bring to four the number of Taiwanese military units assigned to cyberwar and information-related tasks, added the paper.

The defence ministry declined to comment on the report.

Taiwanese government websites have frequently come under cyber attack from China, usually during disputes between the two sides, military authorities say.

In the six months to June last year, hackers launched more than one million attacks on the website of Taiwan's National Security Bureau (NSB), the Liberty Times reported.

The NSB did not reveal how many of the attacks came from China while saying all hacking attempts were blocked.

But the bureau described the perceived cyber threat from the mainland as "very severe" when asked to evaluate it in parliament two months ago.

"China's cyberwar capabilities were organised by the military and government units, using Internet viruses to attack Taiwan's government, economic and military websites," it said in a report cited by the Liberty Times.

However ties between Taipei and Beijing have improved markedly since Ma Ying-jeou of the China-friendly Kuomintang party came to power in 2008 on a platform of ramping up trade and tourism links with the mainland.

Ma was reelected in January 2012 for a second and final four-year term.

Yet China still considers Taiwan part of its territory awaiting reunification, by force if necessary, even though the island has ruled itself for more than 60 years after their split in 1949 at the end of a civil war.