Malaysian Muslims – at around 50,000 by police estimates – gathered in downtown Kuala Lumpur after prayers on Saturday afternoon to protest against a plan by the government to ratify a UN convention which aims to eliminate racial discrimination.
Large numbers of police forces along with security guards were deployed on the streets and major roads were closed.
Dressed in white, the demonstrators chanted "God is great" and waved banners that read "Long live the Malays.”
Pro-government ethnic Malays, who account for around 60 percent of Malaysia's multi-ethnic population, expressed concern that signing the UN pledge could have undermined Malay privileges and threatened Islam's status as the official religion in the southeast Asian nation of 32 million people.
After weeks of pressure by pro-Malay groups, Malaysian Prime Minister Mahathir Mohamad's multi-ethnic government decided last month that it would not ratify the convention, without giving a reason why it was going back on an earlier commitment to sign.
"We are here to defend our rights as Malays," said Faridah Harun, a 59-year-old mother of seven, who travelled down from the northern state of Perak to join the rally with her husband.
"We have ruled this country very well for a very long time, but now there are people who want to take over and do things like shut down MARA," she said, referring to a trust fund for Malays and indigenous people.
"I hope the other races don't challenge the rights of the Malays. As a Muslim, I want Islam to be the first (priority) in Malaysia," said another protester, Arif Hashim, 26.
The Malaysian premier said in a statement published late Friday that the government had no objection to the rally as long as it remained peaceful and orderly.
"On behalf of the government, if the rally is held on the basis of thanksgiving, we are thankful for the support shown," he said in the video posted on his social media pages.
After Malays, the Chinese form the largest minority in the country with 24.6 percent of the population, followed by 7.3 percent Indians and 0.7 percent from national origins.
Muslim Malay majority generally appears to be feeling increasingly insecure under the new Malaysian government, which is claimed to be more representative of minorities.