Police in Zimbabwe’s capital have fired teargas and water cannon in an attempt to quell rioting by minibus drivers and others protesting against what they describe as police harassment.

There has been a surge in demonstrations in recent weeks over increasing economic hardship and alleged mismanagement by the government of the president, Robert Mugabe.

On Monday an Associated Press journalist saw protesters severely beating two police officers with sticks, then taking their uniforms and helmets and wearing them.

The protesters blocked roads leading into the centre of Harare, forcing many people to walk up to six miles (10km) to get to work. Rioters threw stones at police and vehicles, and some children on their way to school were caught up in the chaos.

Armed police in Harare. Photograph: Tsvangirayi Mukwazhi/AP

Outnumbered police later sought to negotiate with the crowds after failing to disperse thousands of protesters, who were concentrated in the eastern suburbs of Harare. Many rioters were young men unable to find regular employment who make a living by charging drivers a small fee to load passengers into minibuses.

The drivers’ grievances stem from anger over roadblocks that police sometimes set up in city streets, which drivers allege are to demand bribes. Police recently promised to reduce the number of roadblocks after complaints from parliamentarians, tourism operators and others.

Such acts of defiance and clashes with the police are rare in Zimbabwe, although in 1998 the government deployed the army against riots over soaring food prices. Mugabe, 92, has ruled the country since independence from white minority rule in 1980, scoffing at frequent allegations of human rights violations.

Frustrations over rapidly deteriorating economic conditions in Zimbabwe, compounded by dissatisfaction over alleged government corruption and incompetence, have resulted in near-daily protests in recent weeks.

On Friday, protesters burned a warehouse at Beitbridge, a busy border post between Zimbabwe and South Africa, over a Zimbabwean decision to ban a wide range of imports.

Seventeen people appeared in court on Sunday over the Beitbridge protests and were charged with public violence.

Separately, state hospital doctors and other government workers said they would strike over the government’s failure to pay their June salaries on time.

The finance minister, Patrick Chinamasa, has pleaded with western countries to unlock financing for Zimbabwe in the form of loans that were halted close to two decades ago. The financing dried up due to failure to repay debts as well as international sanctions imposed because of concerns over democratic rights.

Some recent political protests have been notable for their brazenness. Police said they were looking for Lumumba William Matumanje, a former ruling party activist who used an obscenity to denigrate Mugabe while launching his own political party last week. People have often been sent to jail for such conduct in Zimbabwe.