The human rights situation in Sri Lanka deteriorated markedly during Rajapaksa's first term, and he failed to hold perpetrators accountable. During the final months of the 26-year-long war with the Liberation Tigers of Tamil Eelam (LTTE), which ended with the defeat of the LTTE in May 2009, both government and LTTE forces committed numerous serious violations of international humanitarian law, in which more than 7,000 civilians died in what the UN called a "bloodbath."

"The human rights situation in Sri Lanka plummeted to new depths on Rajapaksa's watch," said Brad Adams, Asia director at Human Rights Watch. "The president deftly played a false conflict between rights and the fight against terrorism in his first term. But with the war over, the UN and other international actors should loudly insist on justice for victims."

Rajapaksa was elected to a second term on January 26, 2010, in a hotly contested election in which his former army chief, retired Gen. Sarath Fonseka, was the runner-up. Although election day was relatively peaceful, according to election monitors, the campaign was marked by hundreds of incidents of violence in which at least four people were killed.

During and after the war, Rajapaksa's government confined nearly 300,000 internally displaced persons to large detention camps, where they were deprived of their liberty and freedom of movement in violation of international law. The government has separated more than 11,000 LTTE suspects from their families at checkpoints and in the camps, denying them due process, such as right to legal counsel and the right to have a court review their detention.

Threats and attacks against outspoken and critical civil society figures increased, and the government used anti-terror laws and emergency regulations against peaceful critics, further diminishing the space for public debate. The hostile, sometimes deadly, media environment drove dozens of journalists into exile.

Enforced disappearances and abductions, a longstanding and widespread problem in Sri Lanka, sharply increased in 2006, when military operations between the government and the LTTE intensified following the collapse of the 2002 ceasefire. In 2006 and 2007, the UN Working Group on Enforced and Involuntary Disappearances recorded more new "disappearance" cases from Sri Lanka than from any other country in the world.

Politically motivated killings during Rajapaksa's first term also remain unresolved, including the extrajudicial executions of five students in Trincomalee in January 2006 and of 17 aid workers with Action Contre la Faim in Mutur in August 2006.

Rajapaksa took no effective steps to bring accountability for human rights violations, Human Rights Watch said. In July 2009, Rajapaksa disbanded, before it could complete its work, a presidential commission of inquiry created in 2006 to investigate 16 cases of grave human rights violations. In April 2008, the International Independent Group of Eminent Persons (IIGEP) had withdrawn from monitoring the commission because it had "not been able to conclude ... that the proceedings of the Commission have been transparent or have satisfied basic international norms and standards."

The vast majority of the hundreds of new "disappearances" and politically motivated killings from the past few years have never been seriously investigated, and none of the perpetrators have been punished.

In May 2009 Rajapaksa promised Ban that the Sri Lankan government would investigate allegations of human rights and laws-of-war violations during the war's final months. No such investigation has taken place. Instead, the government has set up a team of lawyers to respond to allegations about rights violations in reports by the US State Department and the UN special envoy on extrajudicial executions.

Because of the government's failure to investigate serious human rights abuses, Human Rights Watch has long called for an independent international investigation into abuses by all parties to the conflict. Thus far, the secretary-general's office has stated that Ban was "considering" establishing a committee of experts to "assist the government" of Sri Lanka to look at evidence that its soldiers committed war crimes last year.

"The various investigatory bodies set up by President Rajapaksa have spent more energy trying to deflect serious inquiries into abuses than actually conducting them," Adams said. "Ban and key governments should not fall for the same trick again and instead should call for an independent international investigation. The ball is now in Ban's court."