Some 2,000 people marched in the commercial capital, Blantyre, before the protest was broken up, according to Reuters news agency.

It does not mean the incumbent president will be the next president because there will be free and fair elections and the majority of people can vote him out Justice Minister Henry Phoya

In Lilongwe, parliament has started an emergency debate over a proposed change to the constitution to let Mr Muluzi contest elections scheduled for 2004.

The current constitution only allows presidents to serve two terms.

A similar bill was narrowly defeated by parliament last year.

Knives and stones

Some 15 people were arrested by the police and two people were taken to hospital, Reuters reports.

Some of the protesters carried placards reading "Muluzi leave Malawi in peace".

Police say they were worried about violence

Monday's protests were organised by a coalition of Christian groups, civic organisations and political parties.

Some Muslim groups have backed the proposals to let Mr Muluzi stand again.

Supporters of Mr Muluzi armed with knives and stones were also planning to march, reports the French news agency, AFP.

Police said they fired tear gas to prevent clashes between the rival groups.

'No threat'

Following a wave of anti third-term protests last year, Mr Muluzi banned public demonstrations on the issue.

Justice Minister Henry Phoya denied that the new bill threatened democracy, as he introduced it.

"It does not mean the incumbent president will be the next president because there will be free and fair elections and the majority of people can vote him out."

Mr Muluzi's United Democratic Front has 95 MPs and needs an extra 28 votes from the opposition for the two-thirds majority needed to change the constitution.