Sri Lanka's defence ministry on Tuesday ordered troops to shoot on sight people involved in looting or damaging property, a day after mobs targeted the homes of ruling-party politicians.
"Security forces have been ordered to shoot on sight anyone looting public property or causing harm to life," the ministry said.
The country began a curfew on Tuesday after eight people were killed and nearly 200 wounded during the protests over the country's crippling economic crisis.
Police said on Tuesday eight people, including two policemen, were killed and 65 homes damaged during an orgy of violence overnight. Forty-one of the homes were burned.
Prime Minister Mahinda Rajapaksa resigned on Monday to clear the way for a “new unity government”, his spokesman Rohan Weliwita said.
Mr Rajapaksa had to be rescued in a pre-dawn operation by the military on Tuesday after thousands of anti-government protesters stormed his official residence in Colombo overnight, AFP reported.
Police fired tear gas and warning shots to control the crowd.
"After a pre-dawn operation, the former PM and his family were evacuated to safety by the army," a top security official told AFP. "At least 10 petrol bombs were thrown into the compound."
His son Namal, himself once touted as a future national leader, said the Rajapaksa family had no plans to leave Sri Lanka.
"There are a lot of rumours that we are going to leave. We will not leave the country," he said, describing the surge of national anger against his family as a "bad patch".
He added that his father Mahinda would not step down as a lawmaker and wanted to play an active role in choosing his successor.
The Rajapaksa clan's hold on power has been shaken by months of blackouts and shortages in Sri Lanka, the worst economic crisis since it became independent in 1948.
President Gotabaya Rajapaksa remains in office, however, with widespread powers and command over the security forces.
After weeks of peaceful anti-government demonstrations, violence broke out on Monday when Mahinda Rajapaksa's supporters — many of whom had made the journey into the capital from the countryside — attacked protestors with sticks and clubs.
"We were hit, the media were hit, women and children were hit," one witness told AFP, asking not to be named.
Police fired tear gas and water cannons to disperse crowds and declared an immediate curfew in Colombo, a measure later widened to include the entire South Asian nation of 22 million people.
Authorities said the curfew will be lifted on Wednesday morning, with government and private offices, as well as shops and schools, ordered to remain shut on Tuesday.
UN human rights chief Michelle Bachelet condemned the escalating violence and urged the authorities to prevent further unrest.
She urged restraint and meaningful dialogue to address the grievances of the population, after deadly clashes in the worst violence in weeks of protests.
"I am deeply troubled by the escalation of violence in Sri Lanka after supporters of the prime minister attacked peaceful protesters in Colombo yesterday May 9 and the subsequent mob violence against members of the ruling party," Ms Bachelet said in a statement.
"I condemn all violence and call on the authorities to independently, thoroughly and transparently investigate all attacks that have occurred. It is crucial to ensure that those found responsible, including those inciting or organising violence, are held to account."
US ambassador Julie Chung tweeted that Washington condemned "the violence against peaceful protestors" and called on the Sri Lankan "government to conduct a full investigation, including the arrest & prosecution of anyone who incited violence".
Despite the curfew, anti-government protesters defied police to retaliate against government supporters late into Monday night.
Outside Colombo, ruling party lawmaker Amarakeerthi Athukorala shot two people — killing a 27-year-old man — after being surrounded by a mob of anti-government protestors, police said.
"He then took his own life with his revolver," a police official told AFP by telephone.
Mr Athukorala's bodyguard was also found dead at the scene, police said.
Another ruling party politician who was not named opened fire on protesters, killing two and wounding five in the deep south of the island, police said.
Angry crowds set alight the homes of more than a dozen pro-Rajapaksa politicians, along with some vehicles, while buses and trucks used by government loyalists in and around Colombo were also targeted.
Several Rajapaksa homes were torched in different parts of the country, while a family museum was also damaged.
Doctors at the main Colombo National Hospital intervened to rescue wounded government supporters, with soldiers breaking open locked gates to ferry in the wounded.
"They may be murderers, but for us they are patients who must be treated first," a doctor shouted at a mob blocking the entrance to the emergency unit.
