Sri Lanka's former prime minister Mahinda Rajapaksa is facing calls for his arrest from Opposition politicians for inciting violence against peaceful anti-government protesters that claimed at least five lives, left over 200 people injured and saw arson attacks on the homes of several politicians.

Mahinda Rajapaksa, 76, resigned as Sri Lankan Prime Minister on Monday amid unprecedented economic turmoil, hours after his supporters attacked anti-government protesters, prompting authorities to impose a nationwide curfew and deploy Army troops in the capital.

The resignation of the prime minister has automatically annulled the Cabinet and the country is currently being run by his younger brother and President Gotabaya Rajapaksa. Mahinda Rajapaksa has been accused by the Opposition of inciting the ruling party mobs to attack peaceful protesters by making a defiant speech while addressing several thousands of his supporters to deflect calls for his resignation.

"Rajapaksa (Mahinda) must be arrested and brought before the law," M A Sumanthiran, the main Tamil legislator, said in a message. The same sentiments were expressed by former President Maithripala Sirisena and the main Opposition Samagi Jana Balawegaya party's leader Ranjith Madduma Bandara.

"He must be arrested for encouraging violence. There was no reason to attack the peaceful protesters," Sirisena said. The Colombo national hospital said at least 213 people had been admitted for treatment.

One of the protesters who had been brutally assaulted by the Rajapaksa supporters remains in a very critical condition. Mahinda Rajapaksa later resigned, saying he was making way for his brother president Gotabaya Rajapaksa to set up an all-party interim government.

There were reports from all parts of the island of arson attacks on the homes of ruling party politicians, including on the ancestral house of the Rajapaksa family in the deep southern district of Hambantota. Meanwhile, Mahinda Rajapaksa vacated the Temple Trees, the official residence of the prime minister, Tuesday morning, according to media reports.

The police on Monday used tear gas and fired in the air to stop a mob which was trying to break into Temple Trees, the office cum residence of the prime minister. An all-island curfew, which was scheduled to be lifted on Tuesday, was extended last night until Wednesday as arson attacks were reported from most parts of the country.

Army chief General Shavendra Silva called for calm and said the necessary action would be taken to maintain law and order. In the current state of emergency, the troops are given extensive powers to arrest people.

The Opposition parties urged the reconvening of Parliament before the scheduled date of May 17. The trade unions announced that they would launch a continuous strike from Tuesday to protest against the government-backed crackdown on the peaceful protests.

The violence occurred as pressure mounted on the embattled government led by President Gotabaya to form an interim administration to overcome the worst economic crisis facing the country. Sri Lanka is currently in the throes of unprecedented economic turmoil since its independence from Britain in 1948.

The crisis is caused in part by a lack of foreign currency, which has meant that the country cannot afford to pay for imports of staple foods and fuel, leading to acute shortages and very high prices.

Thousands of demonstrators have hit the streets across Sri Lanka since April 9 seeking the resignation of President Gotabaya and Prime Minister Mahinda, as the government ran out of money for vital imports- prices of essential commodities have skyrocketed and there are acute shortages in fuel, medicines and electricity supply.

In a special Cabinet meeting on Friday, President Gotabaya Rajapaksa declared a state of emergency with effect from Friday midnight. This is the second time that an emergency was declared in Sri Lanka in just over a month as the island nation was in the grip of the worst economic crisis.