At least a dozen people were injured after Mozambican police violently dispersed a protest led by opposition leader Venâncio Mondlane, the runner-up in last year's disputed presidential election, Mondlane's team and a civil society group say.

Eyewitnesses and Mondlane's aides said the police fired live rounds at the opposition leader's convoy and the anti-government protesters who had joined him on the streets of the capital, Maputo, on Wednesday.

Neither the police nor the authorities have commented.

The protests came as President Daniel Chapo, who took office in January, was due to sign a deal after talks with other political parties to end months of protests over the disputed election.

Mondlane, who has been calling for the protests, was excluded from the talks leading to the ceremony.

A communique from Mondlane's office said the opposition leader had been leading a procession on Wednesday afternoon when his convoy came under fire.

"A contingent of the UIR [a rapid intervention police unit] rammed into Venâncio Mondlane's convoy and began a barrage of gunfire, using live ammunition and tear gas," it added.

In response to the incident, Interior Minister Paulo Chachine told reporters that the police had a mission to prevent any attempt to disrupt the deal-signing ceremony.

He denied that there had been an attempt to kill Mondlane.

Sixteen people were injured, according to local civil society group Plataforma Decide. The BBC has not been able to confirm the casualty figures.

Mondlane's team said two children from a nearby school had died from the shooting. It said 16 people had been injured, including their camera person, with others seriously affected by tear gas.

In a statement, it said Mondlane's condition was "unknown, and his whereabouts are causing concern among his entire team".

A video shared on social media shows the moment when gunshots started ringing out as the procession approached what looks like an armoured vehicle on the streets. People run for safety and the crowds disappear, while the gunfire continues.

More images of people bloodied from the incident have also been shared online.

A witness, who was among the protesters, told the AFP news agency that police had started shooting, as if it was an "ambush scenario. It was just a march".

"I saw some people bleeding from their wounds. My friend was wounded in the leg. I also saw a child who was shot and lost his life in hospital," AFP quoted 27-year old protester Silvestre Alexandre as saying.

Mozambique's former colonial power, Portugal, has condemned "the unacceptable attack on Venâncio Mondlane's convoy" while calling for "restraint from violence and respect for fundamental rights".

In a post on X, the Portuguese foreign affairs ministry has also offered condolences to the bereaved families.

Since President Chapo took over in January, he has made promises for a broad political dialogue that would include various sectors of the society, in order to end the country's post-election crisis.

Some analysts have however criticised him for excluding Mondlane from the talks.

On Wednesday, Mondlane condemned the political deal, calling it "an agreement of people without the people". He said that protests would continue.

"If they don't do what the people want, they won't govern Mozambique," he said.

Since October, close to 400 people have died in violence linked to the protests, according to civil society organisations.