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 order came as the government deployed tens of thousands of army, navy and air force personnel to patrol tense streets of the capital Colombo and elsewhere after a day of violence.

Police said 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.

Official figures showed that 88 cars and busses were destroyed along with hundreds of motorcycles. 

Sri Lanka is under a state of emergency since Friday giving sweeping powers to the military to arrest and detain suspects.

The government also declared a two-day curfew after pro-government activists on Monday smashed a peaceful month-long protest in the capital demanding the resignation of President Gotabaya Rajapaksa.

The main hospital in the capital said 219 people were wounded in Monday's attacks and admitted for treatment. Another six people were wounded in violence elsewhere.

On Tuesday afternoon, the top police officer in Colombo was assaulted and his vehicle set ablaze by an angry mob which accused him of failing to prevent an attack against peaceful protesters Monday.