Mozambique's opposition leader called his supporters to three days of mourning from Wednesday for 50 people he said were killed by security forces in protests after disputed elections last month.
In a Facebook address watched by tens of thousands of people, Venancio Mondlane again demanded a recount of the October 9 vote which the electoral commission said was won by a landslide by the Frelimo party in power for nearly 50 years.
"We lost 50 people shot by the authorities who were supposed to protect these people," said Mondlane, whose whereabouts are unknown. "They died as martyrs of a revolution, of change."
Neither the police nor the government have confirmed a death toll.
Announcing a new wave of protests against a vote he called fraudulent, Mondlane urged his supporters to wear black for the three days of mourning. They should not return to the streets where they risked being attacked by police officers, he said.
"This is a unique and historic opportunity for us to change the chaotic state of our country," said the 50-year-old.
'Real bullets'
The electoral authority said Mondlane and his Podemos party won 20 percent of the vote compared to 71 percent for Frelimo's Daniel Chapo.
President Filipe Nyusi is due to hand over to Chapo in January if the Constitutional Council confirms the results.
Rights groups have accused authorities of using live ammunition on demonstrators, in the most tense elections in the impoverished country since independence from Portugal in 1975.
Civil society group, the Centre for Democracy and Human Rights (CDD) knew of 65 people killed, its human rights officer Andre Mulungo told AFP.
"The police use rubber bullets and real bullets, including tear gas, with the excuse that they are guaranteeing public order," said Ivan Mausse, researcher at the local anti-corruption NGO, Public Integrity Center (CIP).
"We've never had elections as tense as these in a context where the level of information is higher, where young people realise how much their vote is worth," he told AFP.
An extraordinary summit called by the Southern African Development Community (SADC) on Wednesday must "take concrete actions regarding these human rights violations, including calling out these violations", Amnesty International's deputy director for East and Southern Africa, Khanyo Farise, said.
In a message posted on Facebook, Mondlane also appealed to the SADC summit to "demand respect for the electoral will, an end to police repression and the guarantee of a democratic rule of law in Mozambique".