Six inmates were killed and 35 others injured when guards opened fire to control a riot at a prison on the outskirts of Sri Lanka's capital. Two guards were critically injured.
Unrest related to the Covid-19 pandemic has been growing in the overcrowded prisons in Sri Lanka.
Inmates staged protests at several prisons in recent weeksas the number of coronavirus cases surges.
Police spokesman Ajith Rohana said inmates created unrest on Sunday at Mahara prison, about 15 kilometres north of Colombo.
Officials attempted to control the situation, but "the situation turned into a prison riot", he said.
Prisoners tried to take control of the prison and hundreds attempted to escape.
Inmates “reportedly destroyed most of the property, including offices, inside the prison", Mr Rohana said.
The guards opened fire and hundreds of additional police were sent to help the guards and strengthen security around the prison.
An inmate was killed in similar unrest at another prison last week. Another died in March.
More than 1,000 inmates in five prisons have tested positive for the virus and at least two died.
About 50 prison guards have also tested positive.
Sri Lankan prisons are highly congested, with more than 26,000 inmates crowded into jails with a capacity of 10,000.
Senaka Perera, a lawyer with the Committee for Protecting Rights of Prisoners, said the inmates were frustrated because their pleas for testing and the separation of infected prisoners from others had been ignored by officials for more than a month.
Sri Lanka reported a surge in the disease since last month when two clusters – one centred at a garment factory and the other at a fish market – were recorded in Colombo and its suburbs.
Confirmed cases from the two clusters have reached 19,449. Sri Lanka has reported a total of 23,484 cases, leading to 116 fatalities, since the pandemic began.
