The main opposition candidate in Mozambique's contested general election on Tuesday accused security forces of killing his lawyer, as European Union observers cast doubt on the vote.
Tensions mounted ahead of the release, possibly on Wednesday, of preliminary results from the October 9 presidential and parliamentary polls.
They are expected to show that Frelimo, the party that has governed the southern African nation for the past half a century, is in the lead.
"This was a crime committed by the defence and security forces. There's no doubt about it. The special forces killed Elvino," said Venancio Mondlane, who ran for president as an independent with the backing of the small Podemos party.
Lawyer Elvino Dias was travelling in a car in the centre of the capital, Maputo, with Paulo Guambe, another ally of Mondlane's, when they were ambushed and shot dead overnight on Friday to Saturday.
In a video posted on Facebook, Mondlane accused the security forces of firing at Dias 25 times.
Dias's funeral is expected to take place on Wednesday.
Police said it had launched an investigation into the killings, which Frelimo "vehemently" condemned as the "macabre act".
The European Union, the United States, the African Union and the United Nations have all condemned the killings and urged the authorities to identify the perpetrators.
Election observers from the EU have also raised concern about the legitimacy of the polls, noting "irregularities during counting and unjustified alteration of election results at polling station and district level".
They urged the authorities to conduct the ballot count "in a transparent and credible manner, ensuring the traceability of polling station results".
Official results are still pending from the presidential and parliamentary races.
A spokesperson for the electoral commission who spoke to AFP could not give a firm date for the release of the results but it could be on Wednesday according to the electoral calendar.
Electoral violence is not uncommon in Mozambique. Last year, several people were killed in clashes after Frelimo won municipal elections.
Mondlane, who has already claimed victory, was among a group of several hundred protesters dispersed by police with tear gas on Monday, after he had called for a general strike.
The 50-year-old former radio presenter has urged supporters to again "paralyse the country" on Thursday and Friday over what he predicted would be "profoundly false" results.
The EU has called for "utmost restraint by all" in Mozambique, while the US State Department urged people to "reject violence" and "to turn to peaceful means of filing electoral grievances".
"The only means to challenge results and demand accountability is through the official complaint process," State Department spokesperson Matthew Miller said in a statement.
President Filipe Nyusi, 65, is stepping down after his two terms allowed by the constitution but his party's candidate, 47-year-old Daniel Chapo, was widely expected to win the election.
Frelimo has governed the southern African country of 33 million for half a century.
