Thousands of residents from poor neighbourhoods took to the streets on Wednesday to protest the rising prices of oil, wheat, bread, water and electricity in Mozambique.
In the capital Maputo, police fired rubber bullets as demonstrators smashed shop windows and cars.
At least three people have been killed and several injured. According to witnesses, one of the fatalities was a 12-year-old boy who was shot in the head.
Ambulances drawing up to Maputo’s main hospital carried wounded protesters, correspondent Orfeo de Lisboa reports.
Demonstrators have barricaded the capital's main streets, the road to the airport and roads to the capital main suburb Matola.
On Tuesday, the police banned protests, which were organised through mobile phone SMS messages last week.
At least 142 people were arrested, according to police spokesman Pedro Cossa, who says that police will continue to patrol the streets.
He insisted that officers had not fired live rounds, only rubber bullets.
But protesters dispute this claim.
"The police are killing people... They should not shoot live but they are doing it and it's to kill," one of those wounded, Pedro Americo, told RFI.
Doctor Antonio Assis confirmed that protesters were arriving at Maputo Central Hospital in "extremely serious condition".
In 2008, violent protests over increased bus fares saw six people shot dead by police and dozens injured.
According to the CIA factbook, 70 per cent of the country’s population lives below the poverty line and 21 per cent of population is unemployed.