Police in Indonesia have begun questioning the radical Islamic leader, Abu Bakar Ba'asyir, over alleged links to a series of explosions at Christian churches and a plot to kill President Megawati Sukarnoputri.

Ba'aysir has denied any connection to the Jemaah Islamiah group

The interrogation is taking place at the police hospital in east Jakarta, where Mr Ba'asyir has been detained since Monday after collapsing the day before he was due to be questioned.

The chief investigator, Jeldi Ramahdan, said doctors had now confirmed he was fit and police had prepared a list of 50 questions.

He added that the questioning could last several days, depending on Mr Ba'asyir's health.

Mr Ba'asyir, 64, is alleged by the governments of Singapore and Malaysia to be the spiritual leader of the Jemaah Islamiah militant group, suspected of involvement in last month's bomb attack in Bali, and of links to al-Qaeda. He denies wrongdoing.

'Right to silence'

One of Mr Ba'asyir's lawyers said his client would not answer police questions.

Ahmad Michdan told the AFP news agency: "He is a suspect. He has a right to remain silent."

Three suspects seen before the Bali bombing are still being hunted

Police detained Mr Ba'asyir on 20 October after naming him as a suspect in a series of bomb attacks on churches.

Interviews have been delayed several times since Mr Ba'asyir was arrested because of his ill-health.

Indonesia has been under intense international pressure to crack down on radical Islamic groups since the 12 October bombing on the resort island of Bali, which killed more than 190 people - most of them Western tourists.

Australian investigators believe the Bali bombing was the work of experts, who planned the operation to maximise casualties.

Indonesian police have issued sketches of three people they suspect of being the bombers.