Thousands of Malaysians gathered on Saturday for a two-day protest rally in the capital Kuala Lumpur, calling for Prime Minister Najib Razak to resign over a financial scandal, the media reported.
According to sources, the rally is scheduled to continue until 11.59 p.m. on Sunday, the Malaysian Star reported.
The rally has been declared illegal by the police but organisers have declared that it will go ahead as planned.
It is being organised by civil rights group Bersih, whose name means "clean" in Malay and has been calling for electoral reform.
Najib is accused of siphoning $700 million from a sovereign wealth fund into his personal accounts. The prime minister has denied the claims.
The anti-corruption agency effectively cleared him of wrongdoing earlier this month, saying the money was personal donations.
The protests will also take place in Kota Kinabalu and Kuching cities.