WATCH | Fuel hike protests turn deadly in Zimbabwe

Violent protests in Zimbabwe claimed lives on Monday as soldiers were deployed after the embattled government more than doubled fuel prices, sparking widespread anger.

Protesters burnt tyres and barricaded roads while cars were torched as demonstrations turned violent in the capital Harare and Bulawayo, Zimbabwe's second city.

Accusing the opposition and civil society organisations of being behind the protests, security minister Owen Ncube said: "Regrettably, this has resulted in the loss of life and property including injury to police officers and members of the public."

Ncube did not give numbers or the identities of the dead, but said investigations were underway.

At least 13 people had sustained gunshot wounds in and around Harare, the Zimbabwe Association of Doctors for Human Rights said.

President Emmerson Mnangagwa announced the shock price hikes for petrol and diesel on Saturday in a bid to improve supplies as the country battles its worst gasoline shortages in a decade.

In his televised address late Saturday, Mnangagwa said the price hikes were aimed at tackling a shortfall caused by increased fuel usage and "rampant" illegal trading.

Petrol went up to $3.31 a litre, from around $1.46, and diesel now costs $3.11 a litre, from $1.26 in bond currency.

Zimbabwe's economy has been in a slump for more than a decade, suffering cash shortages, high unemployment and recently a scarcity of staples such as bread and cooking oil.

Shops and banks pulled down their shutters in downtown Harare as riot police patrolled the streets and a military helicopter flew over the capital. Several cars were torched.

As night fell, dozens of soldiers were deployed in both cities, reporters saw.

Nkululeko Sibanda, spokesman for the opposition Movement for Democratic Change party, said their headquarters in Harare was attacked late in the evening.

The attackers, travelling in 10 vehicles, "overpowered our security, rushed into the building with what we think is petrol or paraffin and ...lit the building and escaped."

Budget airline Fastjet cancelled flights to and from Harare "due to the current unrest affecting travel on the streets of Harare".

Protesters turned back drivers and stopped buses from carrying passengers in the two main cities. 

At least 200 people have been arrested, the security minister said.