An investigation has been launched by Sri Lanka's jail authorities on the allegations that a group of inmates from a prison camp in the island nation were used to attack anti-government protesters in Colombo this week, according to a media report on Thursday.

Violence erupted in Sri Lanka on Monday after supporters of former prime minister Mahinda Rajapaksa attacked peaceful anti-government protesters demanding his ouster over the country's worst economic crisis that led to acute shortages of staple food, fuel and power.

Over 200 people have also been injured in the violence in Colombo and other cities.

Sri Lanka prisons have launched an investigation on the allegations raised claiming that a group of inmates from the Watareka Open Prison Camp were used to attack protestors in Colombo recently, Commissioner General of Prisons Thushara Upuldeniya was quoted as saying by the News First website.

Footage posted on social media following the attack on peaceful protests showed locals detaining a group of men who later claimed that they were prisoners from the Watareka Open Prison Camp, the report added.

It was observed that the pants worn by the group of detained men were identical to those worn by people who were among the group that attacked peaceful protests on Monday in Colombo.

The Commissioner-General of Prisons said that the men were not wearing prison fatigues, but were wearing a uniform provided to them by the institutions that employed their services.

The Commissioner-General of Prisons, and another officer will be present at the Human Rights Commission of Sri Lanka on Thursday for an inquiry over the matter.

Several people sustained injuries as the supporters from the ruling SLPP, armed with poles and other objects, attacked 'GotaGoGama' protesters in Galle Face.

The mob destroyed several tents and other structures erected at Galle Face and also attacked some of the demonstrators, demanding the resignation of President Gotabaya Rajapaksa.

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 violence saw arson attacks on the homes of several politicians, including the ancestral home of the Rajapaksas in Hambantota.