Riot police in the Mozambican capital Maputo fired tear gas Monday to disperse a crowd protesting against alleged electoral fraud, days after two opposition allies were shot dead.
Several hundred people, including journalists, scattered as heavily armed police walked down a main street, according to videos posted on social media and an AFP reporter at the scene.
Opposition leader Venancio Mondlane, who ran for president in the October 9 election, had called for a general strike to contest early results showing the ruling Frelimo party ahead.
Shops in Maputo were closed and helicopters hovering above the city of around one million people.
"Venancio", as he is popularly known, was among those dispersed and he later posted a video on Facebook showing him running away from tear gas, surrounded by supporters.
He told reporters that police had tried to stop him from attending the demonstration.
"This morning I couldn't get out of my house. I had people at my doorstep, including the police. It took me an hour to get out," said the 50-year-old.
Tensions rose over the weekend after two Mondlane associates were shot dead in Maputo.
Lawyer Elvino Dias and Paulo Guambe, a candidate from the small Podemos party which backs Mondlane, were in a car when they were surrounded by other vehicles and shot dead on Saturday, witnesses said.
Podemos leader Albino Forquilha confirmed the killings to AFP, while police said an investigation had been launched but did not confirm the identities of the two men.
The European Union, African Union and United Nations have condemned the incident and called on the authorities to identify the perpetrators.
In a statement, UN Secretary General Antonio Guterres called on "all Mozambicans, including political leaders and their supporters, to remain calm, exercise restraint and reject all forms of violence."
The head of the African Union Commission, Moussa Faki Mahamat, said he had "deep concern" over "reported cases of post-election violence and in particular the recent killings".
Last year, several people were killed in clashes after municipal elections were won by Frelimo, the party in power since independence 49 years ago.
Official results are still pending from the presidential and parliamentary results.
A spokesperson for the electoral commission who spoke to AFP could not give a firm date for the release of final results but it could be on Wednesday according to the electoral calendar.
Initial indications of a low turnout in the coastal country of some 33 million people could erode the vote's legitimacy.
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.
Other presidential candidates included Ossufo Momade, 63, of the main opposition party Renamo, and Lutero Simango, 64, of the Mozambique Democratic Movement.
Mondlane, who has already claimed victory, said his call for a general protest on Monday was a "great success."
"The country was paralysed... 95 percent of private and public services across the country were paralysed," he said on Facebook.
He said the strike was followed in the cities of Chimoio, Nampula, Beira, and Maputo among others.
AFP could not verify his claim as no official statements or figures on the strike were available.
