Three Muslims were killed and about 10,000 made homeless after attacks by Sinhalese Buddhist mobs during the week starting June 15.
Violence began in the town of Aluthgama after a rally by the Sinhalese-Buddhist chauvinist group Buddhist Power Force (BBS). It then spread to several other towns.
Muslim-owned shops, houses and vehicles were burnt by the mobs. Police were sometimes present, but did nothing to stop the violence.
The BBS has been engaging in a campaign of anti-Muslim propaganda and violent attacks for several years.
Other Buddhists who criticise the BBS have also been attacked. Watareka Vijitha Thera, a Buddhist monk who is a vocal critic of the BBS, was kidnapped, disrobed and assaulted on June 18.
On June 19, Muslim businesses throughout much of Sri Lanka closed down in a hartal (strike) in protest against the attacks.
In Colombo, a rally called by the Equal Rights Movement attracted nearly 2000 participants from all ethnic groups.
Vickramabahu Karunaratne, the general secretary of the New Socialist Party, told the rally that the government was to blame for the riots. He said: “This is not a sudden eruption. It was organised by ... the iron hand of [defence minister] Gotabhaya.
“The government was retreating last month before the struggles of students, workers, fishers, and other oppressed groups. The regime wanted a way out, a diversion … Hence they decided to create an issue for a pogrom against Muslims.”
Solidarity rallies were also held in Jaffna and other towns in the predominantly Tamil north of the island of Sri Lanka. Students and staff from Jaffna University held a rally on June 19.
The anti-Muslim riots are reminiscent of past pogroms against Tamils. A series of anti-Tamil riots, starting in 1956, culminated in the massacre of an estimated 3000 Tamils in 1983.
These pogroms were a key reason Tamils took up arms to fight for an independent Tamil state. The war ended in May 2009.
Tens of thousands of Tamils were massacred by the Sri Lankan armed forces in the final weeks of the war. The Tamil areas of the north and east of the island remain under military occupation.