The death toll in a roadside gunfight involving a convoy carrying Mozambique's opposition leader Afonso Dhlakama has risen to 20.

"The death toll is now up to 19 deaths from Renamo, and still one civilian (the minibus driver)," AFP quoted police commander Armando Mude as saying on Sunday.

Mude had put the death toll at 10 on Saturday. But on Sunday, he said, "​The police found the 10 other corpses while patrolling in the surroundings."

There have been conflicting accounts of Friday's shootout in central Mozambique with Dhlakama's Renamo party claiming it was an ambush.

But police said armed men in Dhlakama's 12-vehicle convoy opened fire first on a minibus taxi carrying civilians.

"According to our reports, it seems the minibus came too close to Renamo's convoy, who thought it was attacking, so they opened fire," said Mude.

"President Dhlakama is safe and sound and morally very concerned with the path our detractors chose to follow," Renamo spokesman Antonio Muchanga told reporters at a Saturday press conference in Maputo without specifying the leader's whereabouts.

It was the second time in two weeks that a convoy carrying Dhlakama has been involved in a shooting.

The political situation in Mozambique has been tense for months with Dhlakama refusing to recognize the results of 2014 elections and threatening to seize power by force in the northern half of the country.