KINSHASA (Reuters) - An international rights group on Thursday accused Congolese police of summarily executing at least 27 people, some of whom were bound, strangled and mutilated in a crackdown on gangs in the capital Kinshasa last year.

Police in Democratic Republic of Congo denied the allegations in a report by the U.S.-based Human Rights Watch (HRW).

The report, based on interviews with nearly 80 witnesses, victims’ family members, security officials and others, adds to allegation that Kinshasa police executed suspected gang members.

President Felix Tshisekedi, who was sworn in last month, has vowed to clean up human rights abuses by Congo’s security forces that he frequently criticized during the tenure of his predecessor, Joseph Kabila.

Tshisekedi’s spokesman, Vidiye Tshimanga, declined to comment on the report.

Kinshasa’s police chief, General Sylvano Kasongo, accused in the report of close involvement in the operation, denied it had happened.

“The police in Kinshasa did not kill people. We arrest them and bring them before justice. We do not murder,” he told Reuters.

The report said that police carried out Operation Likofi - meaning “punch” in the local Lingala language - between May and December 2018.

During late night swoops, masked police rounded up unarmed young men, killed them and often disposed of their bodies near their homes in an apparent attempt to make the killings appear to be urban crime, the report said.

A witness to one killing last May told HRW the police strangled the victim with a black wire until he started convulsing before dumping his body near his house, it said.

Some of the victims had marks indicating that their arms had been tied behind their backs and at least three had amputated genitals, the report said. Seven other people taken by the police during the operation are still missing, it added.

Prior reports about killings of gang members provoked a fierce backlash by Kinshasa authorities. In 2014, the government expelled the United Nations’ human rights chief in Congo after his office released a report accusing the police of executing at least nine people during a crackdown.

On Tuesday, Congo’s security council declared gang violence one of seven security priorities for Tshisekedi’s administration.