At least 18 people died in violence during the run-up to Democratic Republic of Congo's elections this week, with most shot dead by soldiers from Joseph Kabila's presidential guard, U.S.-based Human Rights Watch said on Friday.
The organisation's toll, based on eyewitness accounts and reports from local rights groups, is higher than most earlier accounts of unrest around the country before and during Monday's presidential and parliamentary vote.
The polls are seen as crucial to stabilising the vast central African country, but have been marred by organisational flaws, alleged fraud and clashes between rival political factions and the security forces.
The worst violence saw 14 people killed last Saturday on the final day of campaigning after authorities cancelled political rallies and used force to clear opposition supporters from the streets of the capital, Kinshasa, HRW said in a statement.
It said a presidential guard convoy opened fire on civilians, killing 12 and injuring dozens more including a pregnant woman. It added that the soldiers may have been retaliating after stones were thrown by opposition supporters.
Elections don't give soldiers an excuse to randomly shoot at crowds, The authorities should immediately suspend those responsible for this unnecessary bloodshed and hold them to account, senior HRW Africa researcher Anneke Van Woudenberg said.
No one from the government was immediately available to comment on the specific HRW allegations on Friday. Security minister Adolphe Lumanu said earlier this week that the presidential guard had not been deployed during the violence in Kinshasa.
It could have been people camouflaged or wearing presidential guard uniforms, (but) no element of the presidential guards was on the streets, he told Reuters on Wednesday.
Other incidents across the country included a hammer attack on an opposition politician at his home and the severe beating of an electoral observer after local people accused her of fraud, HRW said.
With preliminary results from the presidential polls due next week, HRW joined the United Nations and others in calling for calm amid rumours and rising tensions, particularly in the largely pro-opposition capital.
As the announcement of election results nears, it is crucial for all leaders to act responsibly and peacefully, win or lose, Van Woudenberg said.
Leading opposition candidate Etienne Tshisekedi has repeatedly said he will not accept defeat, while three other opposition candidates have called for the vote to be annulled, citing widespread fraud by the government.
(Reporting by Jonny Hogg; editing by Mark John and David Stamp)