Sri Lanka's President Gotabaya Rajapaksa announced his resignation on Saturday, hours after a crowd of angry protesters chased him from his residence, as months of frustration brought on by an unprecedented economic crisis boiled over.

Hundreds of thousands of people massed in the capital Colombo to demand the government take responsibility for mismanaging the nation's finances, and for crippling food and fuel shortages.

Sri Lanka's President Gotabaya Rajapaksa fled his official residence shortly before protesters stormed and overran the compound
Sri Lanka's President Gotabaya Rajapaksa fled his official residence shortly before protesters stormed and overran the compound AFP

After storming the gates of the presidential palace, a throng of protesters walked through its rooms, with some among the boisterous crowd jumping into the compound's pool.

Others were seen laughing and lounging in the stately bedrooms of the residence, with one pulling out what he claimed was a pair of Rajapaksa's underwear.

At around the same time, the leader had boarded a naval craft at the Colombo port and was taken to the island's southern waters, where he let it be known he was finally bowing to months of calls for his resignation.

After storming the presidential palace in Colombo, some protestors swam in the pool at the official residence
After storming the presidential palace in Colombo, some protestors swam in the pool at the official residence AFP

"To ensure a peaceful transition, the president said he will step down on July 13," parliamentary speaker Mahinda Abeywardana said in a televised statement.

Rajapaksa had to be extracted from his residence by troops who fired into the air to keep the crowd outside at bay.

Soon after they stormed the presidential palace, Rajapaksa's nearby seafront office also fell into the hands of protesters.

Dozens of protesters were hospitalised with difficulty breathing after heavy tear gas barrages in Colombo
Dozens of protesters were hospitalised with difficulty breathing after heavy tear gas barrages in Colombo AFP

Prime Minister Ranil Wickremesinghe, the first person in line to succeed Rajapaksa, called a meeting with political leaders and said he was willing to step down to pave the way for a unity government.

But that failed to placate protesters, who stormed the premier's private residence and set it alight after night fell.

Footage shared on social media showed a crowd cheering the blaze, which broke out shortly after a security detachment guarding Wickremesinghe attacked several journalists outside the home.

Protesters in Sri Lanka stormed President Gotabaya Rajapaksa's office after overrunning his residence
Protesters in Sri Lanka stormed President Gotabaya Rajapaksa's office after overrunning his residence AFP

No casualties have been reported in the fire so far, and police said Wickremesinghe and his family were away at the time.

Security forces attempted to disperse the huge crowds that had mobbed Colombo's administrative district earlier in the day, with dozens injured in the resulting clashes.

Sri Lanka's President Gotabaya Rajapaksa fled his official residence shortly before protesters stormed and overran the compound
Sri Lanka's President Gotabaya Rajapaksa fled his official residence shortly before protesters stormed and overran the compound AFP

A spokeswoman for Colombo's main hospital said three people were being treated for gunshot wounds, along with 36 others suffering breathing difficulties after being caught up in tear gas barrages.

Protestors demonstrate outside Galle International Cricket Stadium but the Test series against Australia has not been affected by the political turmoil
Protestors demonstrate outside Galle International Cricket Stadium but the Test series against Australia has not been affected by the political turmoil AFP / ISHARA S. KODIKARA

Sri Lanka has suffered through months of shortages of basic goods, lengthy blackouts and galloping inflation after running out of foreign currency to import necessities.

The government has defaulted on its $51 billion external debt and is seeking an International Monetary Fund bailout.

Thousands of people had poured into the capital for Saturday's demonstration, the latest outbreak of unrest sparked by the crisis.

Police had withdrawn a curfew issued on Friday after opposition parties, rights activists and the bar association threatened to sue the police chief.

Thousands of anti-government protesters ignored the stay-home order and even forced railway authorities to operate trains to take them to Colombo for Saturday's rally, officials said.

"The curfew was not a deterrent. In fact, it encouraged more people to get on the streets in defiance," the defence official said.

Sri Lanka has nearly exhausted its already scarce supplies of petrol, and people unable to travel to the capital held protests in other cities across the island.

Demonstrators had already maintained a months-long protest camp outside Rajapaksa's office demanding his resignation.

The camp was the scene of clashes in May when a gang of Rajapaksa loyalists attacked peaceful protesters gathered there.

Nine people were killed and hundreds were wounded after the violence sparked reprisals against pro-government mobs and arson attacks on the homes of lawmakers.

The unrest comes at the tail end of Australia's ongoing cricket tour of Sri Lanka, with Pakistan's squad also on the island for their upcoming series.

"The Australian Test is coming to an end and we are due to start the Pakistan series," a cricket board official told AFP.

"There is no opposition to having the games. In fact, fans are supportive and we have no reason to reschedule."