Anti-government demonstrators shout slogans during a protest in front of the Fort Railway Station in Colombo on Wednesday. AFP

Then acting-president Ranil Wickremesinghe had declared a state of emergency on July 17. It allows for the military to be given powers to detain people, limit public gatherings and search private property.

The vote passed 120-63 in the 225-member parliament. The other lawmakers abstained. The decree, which gives the president the power to make regulations in the interest of public security and order, has to be approved every month.

Wickremesinghe declared a state of emergency last week as acting president before lawmakers elected him to serve the remainder of Gotabaya Rajapaksa's five-year term until 2024. Rajapaksa fled Sri Lanka after thousands of protesters stormed the president’s official residence and other buildings. He later resigned from Singapore.

Ruling party members who back Wickremesinghe said that while protests were reasonable at the beginning of the crisis, groups that don't believe in parliamentary democracy and want to capture power through unconstitutional means had infiltrated the demonstrators and were creating disturbances.

Opposition parties criticised the emergency as a government move to stifle dissent.

Police said in separate statements that they had arrested activists Kusal Sandaruwan and Weranga Pushpika on unlawful assembly charges.

After Rajapaksa fled, Sandaruwan was seen in social media footage counting a large cache of banknotes found in the president's home.

Police have also released photographs of 14 suspects wanted in connection with an arson attack on Wickremesinghe's home on the same day the president's office and residence were overrun.

Police last week demolished the capital's main anti-government protest camp in a pre-dawn assault that raised alarm among foreign diplomats and rights groups.

Also on Wednesday, Gotabaya was granted permission to stay a further 14 days in Singapore, where he landed two weeks ago via Maldives, two sources familiar with the matter told Reuters. The extension will last until Aug.11, they said.

If Gotabaya returned to Sri Lanka, he might not be protected under law if any charges were filed against him, legal experts said.

Sri Lanka's Supreme Court extended overseas travel ban till Aug.2 on former prime minister Mahinda Rajapaksa and former finance minister Basil Rajapaksa.

Basil, younger brother of Gotabaya, was recently prevented from leaving Sri Lanka following protests by passengers and officials at the airport.

Agencies