The government is seeking to challenge a court decision that allowed three ethnic Indian activists facing sedition charges to walk free this week.

The three activists, from rights group Hindraf which mounted the protest, faced three years in jail for speeches earlier this month in which they criticised preferential treatment for Muslim Malays who dominate the population.

State news agency Bernama said the attorney-general had applied for a revision of the court ruling, which found that the charges against the three were unclear and not properly documented.

The court had issued them with a "discharge not amounting to an acquittal," a decision which will be challenged at the High Court next week, Bernama said.

"We are appalled and shocked by the government's decision to try and revise the order," said their lawyer M Manoharan.

"If the charges were once found groundless, it's forever groundless and we don't see any merit in trying to reinstate a groundless charge," he said.

Unlawful assembly outside temple

Hindraf said the speeches touched on freedom of religion and inequality for ethnic Indians, who make up eight percent of the population, against Malay Muslims at 60 percent and ethnic Chinese at 26 percent.

Manoharan said that at least 100 protesters were charged on today over weekend demonstrations that have rocked the government, which rarely faces open opposition. They face six months in jail if convicted.

He represented 40 people who were accused of holding an unlawful assembly outside Batu Caves, an important Hindu temple on the outskirts of Kuala Lumpur, on Saturday ahead of Sunday's main street demonstrations.

"How can they be charged with unlawful assembly outside a temple when it is a place of worship?" he asked. "This is a violation of their freedom of religion as guaranteed under the constitution."