Sri Lankan president Gotabaya Rajapaksa was caught in a standoff on Tuesday with airport immigration staff who blocked him from leaving the country.

Mass street protests have spread across the country and thousands of anti-government protesters stormed into and occupied the presidential palace on Saturday demanding Mr Rajapaksa’s resignation over an unprecedented economic crisis that has resulted in severe hardship to ordinary citizens.

The government has insisted that 73-year-old Mr Rajapaksa, who for months refused to resign “under any circumstances”, will officially step down from his post on Wednesday.

The president had fled from his official residence before thousands of people had stormed into his Colombo palace.

Immigration officers at the airport refused to go to the VIP suite to stamp his passport to allow him to fly to the United Arab Emirates (UAE), sources told AFP. The president had refused to go through public facilities fearing backlash from other passengers.

Mr Rajapaksa and his wife allegedly spent the night at a military base located near the international airport next to the main international airport after missing “four flights”.

Although his whereabouts have been kept away public eye, he is believed to be holed up on a naval vessel in Sri Lankan waters.

His brother and former finance minister Basil Rajapaksa was also barred from flying out of the country to Dubai on the same day after immigration staff refused fast-track service to him.

The 71-year-old also holds US citizenship and had resigned as finance minister in early April amid growing calls for the Rajapaksa clan to step down over a severe shortage of fuel and other necessities.

“Given the unrest in Sri Lanka, immigration officials are under tremendous pressure to not allow top-level people to leave the country,” KAS Kanugala, chairman of the Sri Lanka Immigration and Emigration Officers Association, told Reuters.

“We are concerned for our security. So until this issue is resolved, the immigration officials working at the VIP lounge decided to withdraw their services.”

Locals took to social media to express their ire after pictures of Mr Rajapaksa at the lounge in efforts to leave the country were reported by local media.

The cash-strapped island nation of 22 million has largely blamed the Rajapaksa family, including Mahinda Rajapaksa, who has served as both president and prime minister, for the worst financial crisis since independence in 1948.

Six Rajapaksas were serving in the cabinet and Gotabaya Rajapaksa’s exit from office will mark a temporary end to the family’s reign in Sri Lanka.

Reports suggested that the president has already signed a resignation letter dated 13 July that will be handed over to the parliament speaker on Wednesday. But protesters have vowed to stay put in the president’s official residence until the resignation becomes official.

Over the weekend, livid protesters had also set fire to prime minister Ranil Wickremesinghe’s private residence in Colombo, forcing him to offer his resignation as well.

Mr Wickremesinghe, a veteran politician who took over the post in May from Mahinda Rajapaksa, said he would step down once opposition parties agree to form a unity government.

Meanwhile, opposition leader and chief of Samagi Jana Balawegaya party Sajith Premadasa, has expressed his intention to run for the president’s office.

Mr Premadasa told the BBC that his party and allies had agreed to put “my nomination for the position of presidency, if a vacancy occurs”.

Dullas Alahapperuma, a lawmaker and former minister, has been reportedly proposed for the prime minister’s post. The Sri Lankan parliament will elect a new president on 20 July to form an all-party government.

Colombo is holding negotiations with the International Monetary Fund (IMF) for a $3bn bailout package to fix the “collapsed economy”.