Colombo/Singapore, Jul 14: Sri Lankan President Gotabaya Rajapaksa on Thursday emailed his resignation letter to the Speaker, soon after he was allowed by Singapore to enter the city-state on a "private visit", ending the suspense over his future in the face of massive public revolt against his government's mishandling of the economy.

A Saudi airlines flight - SV 788 - carrying Rajapaksa arrived in Singapore from the Maldives where he had fled early Wednesday without resigning as promised to avoid the possibility of arrest by the new government. Sri Lanka Economic Crisis: Protestors Celebrate at Galle Face Park Following the Resignation of President Gotabaya Rajapaksa (Watch Video)

Speaker Mahinda Yapa Abeywardena's media secretary Indunil Abeywardena on Thursday night said a resignation letter from President Rajapaksa has been received through the Sri Lanka High Commission in Singapore.

"The Speaker wishes to inform that an official statement on this would be made tomorrow (Friday) after the verification process and legal formalities," Abeywardena said in a brief statement.

The Speaker wants to see the original signature. The original will be brought to Colombo from Singapore in the next available flight by a diplomatic officer, sources said.

The development comes on a day when anti-government protesters announced to vacate some of the administrative buildings, including the President's House and the PM Office, they have been occupying since April 9 demanding Rajapaksa's ouster.

With Rajapaksa's resignation Prime Minister Ranil Wickremesinghe will be the President.

Rajapaksa, the 73-year-old leader who had promised to resign on Wednesday instead appointed Prime Minister Wickremesinghe as the Acting President hours after he fled to the Maldives, escalating the political crisis and triggering a fresh wave of protests in the island nation.

From the Maldives, he went to Singapore on Thursday.

A spokesperson for Singapore Ministry of Foreign Affairs confirmed that Rajapaksa has been "allowed entry into Singapore on a private visit".

He has not asked for asylum and neither has he been granted any asylum, the spokesperson said, adding Singapore generally does not grant requests for asylum.

Speaker Abeywardena earlier Thursday informed Rajapaksa that he should submit his resignation letter as soon as possible or else he will consider other optios to remove him from the office.

A spokesperson for the Sri Lanka Parliament said that given that the President had not yet tendered his letter of resignation, it is uncertain if Parliament would be convened on Friday.

Prime Minister Wickremesinghe, who is now Acting President, on Wednesday informed the Speaker to nominate a Prime Minister who is acceptable to both the Government and Opposition.

President Rajapaka's brothers - former prime minister Mahinda Rajapaksa and ex-finance minister Basil Rajapaksa - on Thursday gave an undertaking to the Supreme Court through their lawyers that they will not leave the country until the Fundamental Rights petition filed against them is heard on Friday, the Daily Mirror reported.

A five-judge bench of Lankan Supreme Court comprising Chief Justice Jayantha Jayasuriya, Justice Buwaneka Aluwihare, Justice Priyantha Jayawardena, Justice Vijith Malalgoda, and Justice LTB Dehideniya are scheduled to hear on Friday the petition against the two members of the erstwhile powerful Rajapaksa family.

Mahinda, the patriarch of the Rajapaksa clan, resigned from the post of prime minister on May 9, hours after his supporters attacked anti-government protesters outside President Rajapaksa's office.

The 76-year-old former strongman was barred by a Sri Lankan court from travelling abroad in May in view of investigations against them for the deadly attack on anti-government protesters in Colombo.

Basil, a US passport holder, resigned as finance minister in early April as street protests intensified against shortages of fuel, food and other necessities and quit his seat in parliament in June.

Meanwhile, the Sri Lankan Army in a statement urged the protesters to desist from violence immediately or be prepared to face the "consequences", warning that the security forces are "legitimately empowered" to exercise force.

At least 84 people were hospitalised when protesters clashed with the security forces at the PM office and at the main access junction to Parliament on Wednesday after President Rajapaksa fled the country. The police fired tear gas and water cannons at the mob who were trying to break barriers and enter the restricted zone.

Authorities on Wednesday imposed a curfew in the Western Province following the eruption of violence. The curfew was lifted in the morning. But it had to be reimposed amid fears of violence as there was no word from Rajapaksa on his resignation.

The Army said that despite its repeated appeals the "unruly protesting mobs" on Wednesday tried to forcibly enter Parliament complex aggressively went on harassing and attacking the troops on duty using clubs, iron rods, stones, helmets, etc and snatched TWO T-56 weapons with ammunition rounds and caused injuries to a dozen of Army personnel.

It said the army troops used minimum force and brought the situation under control.

Wednesday's protests were more directed at Wickremesinghe. Calls for his resignation intensified after he was appointed the acting president. Political party leaders are asking him to step down so that Speaker Abeywardena can take control as acting president.

Sri Lanka, a country of 22 million people, is under the grip of an unprecedented economic turmoil, the worst in seven decades, leaving millions struggling to buy food, medicine, fuel and other essentials.