COLOMBO, Sri Lanka >> Sri Lanka’s government must account for ethnic minority rebels and others who were detained at the end of the country’s civil war almost two years ago because some appear to have disappeared, a rights group said Friday.

New York-based Human Rights Watch said at least 20 Tamil Tiger rebels arrested in May 2009 are unaccounted for.

It urged a United Nations panel investigating wartime actions by both sides to probe those cases as well.

“The Sri Lankan government needs to respond to all allegations of disappearances with more than a ritual blanket denial,” Brad Adams, the group’s Asia director, said in a statement. “Family members of the disappeared have the right to know if their loved ones are alive or dead.”

The group said the missing people include a Catholic priest who was trapped in the war zone and some rebel fighters who surrendered to the army and were seen being loaded into a bus. Witnesses said the wife and two children of another rebel were also taken on the bus but there was no information about what happened to them, the group said.

One of the people taken was Yogaratnam Yogi, a rebel political leader and a former peace negotiator, it said. The human rights group said it also has obtained several video clips showing a senior rebel fighter known as “Col. Ramesh” in military custody. The government declared Ramesh was killed in fighting.

Military spokesman Maj. Gen. Ubaya Medawala denied the allegations.

“This is an old story. We have declared the names of all those whom we arrested and the family members are visiting them,” he said.

Sri Lankan troops crushed the Liberation Tigers of Tamil Eelam rebels in May 2009, ending their 26-year fight for an independent state for ethnic minority Tamils.

Both sides were accused of targeting civilians, and human rights groups have demanded that they be investigated for war crimes.

Between 80,000 and 100,000 people were killed in the war, including at least 7,000 civilians in the final months of the conflict, according to the United Nations.