Supporters of the Mozambican opposition leader, Venâncio Mondlane, were injured as the police tried to break up the crowd that had met him after he returned from exile on Thursday.
He left the country saying he believed his life was in danger after the controversial presidential election in October that sparked deadly protests.
Mondlane landed at the capital's main airport, Maputo, amid tension and heavy security, with thousands gathered to welcome him.
He came back before Daniel Chapo was sworn in as president next week. He was a candidate for the ruling Frelimo party, and was confirmed as the winner of the October poll by the constitutional court.
The last official results announced by the highest court in the country just over a fortnight ago gave Chapo 65% of the vote and Mondlane, in second place, with 24%.
Frelimo has been in power for the past five decades since independence from Portugal.
After coming out of the airport building, a video shows Mondlane kneeling on the ground with a Bible in hand receiving cheers from supporters.
The 50-year-old Pentecostal preacher began to pray and then declared that he had won the election.
“I, Venancio Mondlane, president elected by the Mozambican people… elected by the true will of the people – swear on my honor to serve the Mozambican homeland and its people,” he said.
He said he was returning to be closer to the protest movement that has seen weeks of national demonstrations in which dozens of people have been killed.
Supporters turned out in large numbers to welcome Mondlane (Reuters)
On Thursday, two people were killed and injured near one of the capital's main roads after a short rally held by Mondlane.
Witnesses said that as the police were trying to disperse the crowd, he was shot. The two injured were then taken to a nearby private clinic.
There are other reports of unconfirmed deaths.
In his first comments Mondlane said he was ready to talk about how to resolve the tension over the disputed survey, which he says was stolen from him.
“I'm here in the flesh to say if you want to negotiate… I'm here,” he said.
He said he had returned to speak out against “atrocities” he said were being committed against his supporters and to defend himself against allegations of criminal responsibility.
He also said that he would “continue to fight for this country and prevent the current situation from continuing”.
Mondlane has been organizing protests through broadcasts on Facebook, but over the weekend he announced he was returning, saying “they don't have to go after me anymore”.
In a defiant message he said: “If (the authorities) want they can kill me, but the fight will continue”.
Before he landed, the airport was heavily guarded by police officers trying to prevent Mondlane's supporters from reaching the area.
Mondlane said it was a “unilateral decision” that was not the result of any political agreement. He has previously said that he would apply himself as president on January 15.
Since the October election, waves of protests have left more than 270 people, including activists, children and members of the security forces dead, according to rights groups.
The protests and the violent crackdown by security forces have tested the stability of the country and there have been concerns that it would worsen if anything happened to Mondlane.
You might also be interested in:
(Getty Images/BBC)
go to BBCAfrica.com for more news from the African continent.
Follow us on Twitter @BBCAfricaon Facebook at BBC Africa or on Instagram at bcafrica
