Sri Lankan Police imposed an indefinite curfew in Colombo on Monday after government supporters clashed with demonstrators demanding the resignation of President Gotabaya Rajapaksa.
Sources reported that as many as 20 people have been injured in the clashes.
Rajapaksa supporters armed with sticks and clubs attacked unarmed protesters camping outside the president's office since April 9, AFP added.
Police fired tear gas and water cannon on the government supporters who breached police lines to smash tents and other structures set up by anti-government protesters.
The violence took place even as reports on Monday indicate that Mahinda Rajapksa may offer to resign as Prime Minister as pressure mounts on the embattled government led by his younger brother and President Gotabaya to form an interim administration to overcome the worst economic crisis facing the country.
Rajapaksa was gathering his supporters to apply counterpressure not to stand down, sources reported.