The UK-based rights group said Guinean security forces fired live rounds at protesters during post-election unrest.
Nearly two dozen people have been killed in violence that erupted following a disputed presidential election in Guinea last week, state television reported on Monday, as international envoys attempted to soothe tensions in the West African nation.
The RTG state news channel said 21 people had been killed since October 19, including officers of the security forces – six fewer than figures compiled by the opposition, which claims 27 have died.
President Alpha Conde, 82, won a hotly contested October 18 election, according to official results announced on Saturday, setting the stage for a controversial third term.
But his main opponent Cellou Dalein Diallo, 68, disputes the results. He claimed victory last week, citing data his supporters gathered at individual polling stations.
Diallo’s self-proclaimed victory led to a week of clashes between his supporters and security forces across the nation.
The government had previously put the number of those killed at 10.
Much of the turbulence centres on the possibility of a third term for Conde, whom opponents accuse of drifting into authoritarianism.
He pushed through a new constitution in March, arguing it would modernise the country. But it also allowed him to bypass a two-term limit for presidents.
A diplomatic delegation from the United Nations, African Union and the 15-nation Economic Community of West African States landed in Guinea on Sunday in the aftermath of the unrest.
The envoys – who include ECOWAS Commission President Jean-Claude Kassi Brou and the UN special representative to West Africa, Mohamed Ibn Chambas – met several ministers and government officials on Monday.
An ECOWAS official in Conakry said they also spoke with representatives of Guinea’s electoral commission and foreign diplomats.
Diallo told AFP news agency that the envoys met with him as well at his Conakry home, which the police have blockaded for days. Meanwhile on Tuesday, the envoys urged the government to lift the blockade of Diallo’s home.
Anti-Conde protests were due to resume in the city early on Monday and many shops stayed shut, but few people ended up hitting the streets in the end.
“In my neighbourhood, people say they are waiting to see the outcome of the joint mission,” said a suburban resident who declined to be named.
Scars from the unrest were apparent in the Conakry neighbourhood of Wanindara – an opposition stronghold – with burned-out vehicles lying on the roadside.
Mohamed Saliou Camara, whose house was torched, said Conde and Diallo supporters had clashed in the area.