Former Zambian President Frederick Chiluba is under 24-hour surveillance to keep him "indoors" and stop him being being harmed by an angry public, according to the government.

The BBC's Penny Dale in Lusaka said this means Mr Chiluba is under virtual house arrest, although this has been denied by the authorities.

The government move follows the high court decision on Wednesday to stop any prosecution of Mr Chiluba on corruption charges until the court has decided whether parliament's lifting of his immunity from prosecution is legal.

The mood in the nation is against him

Kennedy Sakeni, Deputy Home Affairs Minister

Mr Chiluba asked the court to nullify the parliamentary decision on the grounds that he was not given a chance to defend himself, according to his lawyer Robert Simeza.

On Tuesday, parliament voted to lift his immunity from prosecution after President Levy Mwanawasa outlined corruption charges against him last week.

The Zambian Government has ordered the police to give Mr Chiluba round-the-clock protection to prevent unruly citizens from harming him, Home Minister Luckson Mapushi told the French news agency, AFP, on Thursday.

"Our assessment is that some people may decide to harm him," he said.

He denied that Mr Chiluba was under house arrest.

Sneaking out

There has been no public response so far from Mr Chiluba to the surveillance decision, according to the BBC's correspondent.

She told BBC News Online that there had been no obvious threat to him from the public and the area around his house was quiet with no demonstrators.

There have been public calls for Mr Chiluba's arrest

The Deputy Home Affairs Minister, Kennedy Sakeni, told Reuters news agency that "Chiluba has been placed under surveillance in order to safeguard public interest".

"It is a precaution to make sure that he stays indoors and is not harmed by anybody because the mood in the nation is against him. If Chiluba sneaks out, Zambians will not take that kindly," he said.

Not alone

The actions against the former president are part of an anti-corruption drive by President Mwanawasa.

On Wednesday, the president said that anyone caught up in the corruption drag net would be accorded a fair trial.

Despite the action against Mr Chiluba and several other leading public figures, civil society groups continue to demand more action, pointing out that many of Mr Mwanawasa's cabinet ministers also served under Mr Chiluba.

"It is clear that Chiluba did not steal alone," a spokesman for the anti-corruption campaign group, the Oasis Forum, said on Wednesday.

No date has been set for the review of the parliamentary decision on Mr Chiluba's immunity.