NEW DELHI — Sri Lanka’s president, Mahinda Rajapaksa, tried to pre-empt criticism of his government’s human rights record on Friday as he welcomed leaders of Commonwealth countries to a summit meeting in the Sri Lankan capital, Colombo, that was overshadowed by persistent allegations of state-sponsored abuse during a long civil war by the Sinhalese-dominated government against ethnic Tamils.

The prime ministers of Canada, India and Mauritius stayed away from the meeting to protest Sri Lanka’s lack of accountability for abductions, killings and other abuses by government forces that reportedly took place in the waning days of the war. Britain’s prime minister, David Cameron, made a point of traveling to the northern district of Jaffna, where the country’s Tamil population is concentrated. He was surrounded by protesters who tried to hand over photographs of their missing relatives, local media reported.

Mr. Rajapaksa made an oblique reference to the controversy by quoting Buddha in his opening remarks at the three-day meeting, which was televised. “Let no one take notice of the faults of others or what they have done or not done,” he said. “Let one be concerned only about what one has done and left undone.”

Leaders of most of the Commonwealth’s 53 countries gathered in Colombo for an event the authorities had hoped would draw attention to the country’s postwar revival.