Malaysia has blocked the website run by organisers of a large anti-government protest planned for this weekend.
A BBC check found the Bersih.org website could not be accessed on Malaysian mobile phones and computers.
Authorities warned on Thursday that sites which promoted and spread information about the demonstration would be blocked.
Protest organisers are calling for Prime Minister Najib Razak to step down over allegations of corruption.
Mr Najib is accused of siphoning $700m (£452m) from a sovereign wealth fund into his personal accounts, a claim he has denied.
The anti-corruption agency effectively cleared him of wrongdoing earlier this month, saying the money was personal donations.
The Bersih 4.0 protest is due to be held across three cities in Malaysia over the weekend, including Kuala Lumpur. Thousands are expected to rally in the capital alone.
It is being organised by civil rights group Bersih, whose name means "clean" in Malay and has been calling for electoral reform.
But authorities have said the protest is illegal, setting the stage for a possible showdown with security forces. Previous anti-government Bersih rallies saw large turnouts and clashes with the police.
The Malaysian Communications and Multimedia Commission said on Thursday the protest would "threaten" public order and social harmony.
What is 1MDB?
- The 1Malaysia Development Berhad state investment fund was started by Prime Minister Najib Razak in 2009 to turn Kuala Lumpur into a financial hub and develop the national economy.
- It began attracting attention at the end of 2014 when it started missing payments. It later emerged that the fund was mired in $11bn (£7bn) of debt.
- Mr Najib, who is the chairman of the fund's board of advisers, has been accused of taking $700m from the fund - a charge which he has denied and blamed on a political smear campaign.
- The anti-corruption agency agreed with Mr Najib in August that the money was donations.