Sri Lanka: Prime minister quits after his supporters attack anti-government protesters
The country has suffered months of blackouts and dire shortages of food, fuel and medicines in its worst economic crisis since independence, sparking weeks of overwhelmingly peaceful anti-government demonstrations.
Rajapaksa's spokesman Rohan Weliwita said the 76-year-old sent his letter of resignation to his younger brother, President Gotabaya Rajapaksa, clearing the way for a "new unity government".
"I am resigning with immediate effect so that you will be able to appoint an all-party government to guide the country out of the current economic crisis," the prime minister said in the letter, seen by AFP.
The country's largest opposition party said before the clashes that it would not join any government helmed by a member of the Rajapaksa clan.
The resignation of the prime minister automatically means the cabinet stands dissolved.
On Monday the biggest clashes since the start of the crisis erupted in Colombo when supporters of the Rajapaksa family went on the rampage, AFP reporters at the scene said.
Police fired tear gas and water cannon and declared an immediate curfew in Colombo which was later widened to include the entire South Asian island nation of 22 million people.
At least 78 injured people were hospitalised, Colombo National Hospital spokesman Pushpa Soysa told AFP.
Officials said the army riot squad was called in to reinforce police. Soldiers have been deployed throughout the crisis to protect deliveries of fuel and other essentials but until now not to prevent clashes.
The US ambassador to Sri Lanka condemned "the violence against peaceful protestors today, and call on the government to conduct a full investigation, including the arrest & prosecution of anyone who incited violence".
"Our sympathies are with those injured today and we urge calm and restraint across the island," Julie Chung tweeted.