Security forces in the Democratic Republic of Congo have reportedly killed at least 24 civilians since a disputed presidential election last month.
President Joseph Kabila was sworn in for a second term this week, but his rival, Etienne Tshisekedi says he won.
The Human Rights Watch group says most of the deaths occurred in the capital, Kinshasa, where Mr Tshisekedi has strong support.
It said it had evidence that the security forces tried to cover up the deaths.
The elections were the first to be organised locally since the end of a civil war in 2003, which left some four million people dead.
The results were announced on 9 December, but were immediately rejected by Mr Tshisekedi and his supporters.
Western observers said the electoral process had been too flawed to be credible.
Human Rights Watch says the operations are aimed at opposition activists.
