A United Nations human rights expert says Malaysia's “heavy-handed” response to a demonstration for clean elections on Saturday risks undermining democratic progress in the country.

Frank LaRue, an unpaid special envoy on the right to freedom of expression, said Monday that actions taken by the government before and during Saturday's demonstration “unduly restricted the rights to freedom of expression, assembly and association.”

More than 100 organizers were arrested before of the rally, which drew tens of thousands of people to Kuala Lumpur to demand electoral reforms ahead of elections next year. Authorities declared the protest illegal and dispersed the demonstrators with tear gas and water cannons, detaining hundreds of people for several hours.

LaRue said there was no credible evidence to support official claims that the rally was a threat to national security or aimed at toppling the government.

In a separate statement, U.N. expert El Hadji Malick Sow expressed deep concern about six individuals who have been detained under a Malaysian emergency ordinance since June 25. Malick, who chairs a U.N. working group on arbitrary detention, reiterated a year-old recommendation by the group that the ordinance be repealed.

Both experts reminded Malaysia of its obligations to uphold the highest human rights standards as a member of the U.N. Human Rights Council and a signatory to the Universal Declaration of Human Rights.

The two experts report to the Human Rights Council in Geneva.