COLOMBO: A Sri Lankan court on Wednesday sentenced two people to prison sentences of 290 and 300 years for their involvement in the assassination attempt of a former president nearly 16 years ago.

Judge Pathmini Ranawaka Gunathilake found Velayutham Varatharajah and Chandra Ragupathy guilty of conspiracy and also aiding and abetting the now defeated Tamil Tiger separatist rebels in their attempt to kill then-President Chandrika Bandaranaike Kumaratunga by exploding a powerful suicide bomb during an election rally in the capital in December 1999.

The blast killed 26 people and wounded 80, including Kumaratunga, who lost one eye. A third suspect had previously been sentenced to 290 years. The fourth suspect was released on Wednesday.

Sri Lankan forces defeated the rebels in 2009, ending a decades-long civil war.

During the height of the war, the Tamil rebels were accused of dozens of suicide blasts, including ones that killed former Sri Lankan President Ranasinghe Premadasa and former Indian Prime Minister Rajiv Gandhi.

Meanwhile, the United Nations said on Wednesday that Sri Lanka must investigate reports of secret places of detention and set up a “credible and independent” body to clarify the fate of people missing since the long war that ended in 2009.

Some Tamils allege that the military maintains detention centers and tortures former Tamil rebels who surrendered after defeat. The military rejects the charge. Tamils who went missing in the war’s final phase are alleged to range from many thousands to a few hundred.

“Reports have continued to suggest the existence of secret and unacknowledged places of detention. These require urgent investigation,” Zeid Ra’ad Al-Hussein, UN High Commissioner for Human Rights, said in a speech.

The presidential commission to investigate missing persons should be “disbanded and its pending cases transferred to a credible and independent institution,” he said.

The government has yet to clarify the number and identity of detainees still held under the Prevention of Terrorism Act, Zeid said, citing credible reports from activists that 19 people have been arrested this year and some have been tortured.

Surveillance and interference continue in the mainly Tamil areas in the north and east, “including harassment and intimidation by military and intelligence services,” he said, calling for fundamental reform of the security sector.

He was addressing the UN Human Rights Council in Geneva by videolink from New York a day before the 47 member state forum is expected to adopt a resolution that seeks justice for victims of the 26-year war.