Also Tuesday, a group of Chen supporters announced a mass protest against his jailing on corruption charges.

Chen, 57, has refused solid food since early Wednesday of last week, after a three-judge panel ordered him locked up, while prosecutors pursue bribery and other graft allegations against him.

Chen was moved from a suburban Taipei jail late on Sunday to a nearby hospital, after doctors observed that he was suffering from an irregular heartbeat. He began the hunger strike to protest what he called the 'political persecution' involved in his arrest.

Speaking to reporters on Tuesday, Dr Yang Chang-bin said Chen was continuing his hunger strike but that he was not in danger.

'(He) still doesn't want to eat,' Dr Yang said. 'Chen is conscious and his condition has improved.'

Dr Yang gave no indication how long Chen was likely to be treated at the hospital. The former leader has rejected pleas by family members to end his fast.

Meanwhile, Chen supporters announced plans for a mass demonstration at a Taipei park on Saturday.

Speaking to reporters at Chen's office in downtown Taipei, former Premier Chang Chun-hsiung said the new government of President Ma Ying-jeou was treating Chen unfairly, and that the demonstration was meant as a response.

'The authorities have violated human rights,' Mr Chang said.

Chen has tried to portray his arrest as an effort by Mr Ma's government to muzzle his anti-China, pro-independence views.

Since entering office in May, Mr Ma has pushed hard for closer economic cooperation across the 160-kilometre-wide Taiwan Strait, and ending the long running competition between Beijing and Taipei for diplomatic allies.

The two sides split amid civil war in 1949.

All that - and Mr Ma's ultimate desire to sign a peace treaty with the Communist leadership in Beijing - is anathema to Chen, who rejects China's claim that Taiwan is part of its territory, and supports formal independence for the island of 23 million people. -- AP