His statement from prison, which was read by his wife Azizah Ismail, said the government should not use police power "to hit and kick the people".

Mr Anwar also:

• called on the police to refrain from "wanton beatings" of protesters

• urged his followers to campaign peacefully

• again called for Prime Minister Mahathir Mohamad to resign.

Amnesty International have also criticised the police for excessive use of force and warned of a risk of further violence.

"It is feared that the authorities will increasingly cite public order concerns to further restrict the right of assembly, and to justify the use of force against peaceful demonstrations," the organisation said.

The criticisms followed clashes between anti-government demonstrators and riot police in which more than 240 people were detained and come as demonstrators planned a rally on Tuesday to protest against the use of the Internal Security Act (ISA).

Water cannon and tear gas

Amnesty says police used excessive force

Two policemen and 12 protesters were injured when a full-scale riot broke out over the weekend at a street protest in Kampung Baru in the heart of the capital Kuala Lumpur.

Nearly 2,000 demonstrators had gathered at a mosque in a show of support for Mr Ibrahim, who was detained last month, accused of corruption and sexual offences.

Riot police fired tear gas and water cannons at protesters who retaliated by hurling stones and bricks.

Dr Mahathir: 'They were armed for a fight'

The weekend riot witnessed the most serious violence in the current unrest - the worst the country has seen since 1974.

Dr Mahathir says rioters used women as human shields

But Dr Mahathir defended the police action saying protesters had come armed for a fight.

He said authorities discovered Molotov cocktails and kerosene at the scene.

He also accused rioters of using women and children as "shields" for protection against police.

Mr Anwar has accused authorities of conspiring to sideline him from power and prevent him from exposing corruption and cronyism.

Dr Mahathir has said his former deputy is morally unfit for office.

Mr Anwar, who is still in custody, appeared in court last month with a black eye he said had been inflicted while in police custody.