A protest by Zimbabwean transport drivers turned violent as police fired teargas and water cannons on protesters. The country has been shaken by demonstrations against government corruption and shortages of money.
The police arrested some 30 people on Monday after minibus and taxi drivers hurled rocks at security forces.
The protesters blocked roads and burned tires in the eastern part of the capital Harare amid increasing anger against President Robert Mugabe's government.
In the past weeks, the African country has witnessed a surge in public demonstrations against corruption and the government's plan to circulate local bank notes amid a slowing economy.
Most Harare protesters were unemployed young men who make a living by offering taxi service to the locals. The transporters accuse authorities of seeking to raise money for their operations by imposing hefty fines on their vehicles.
But officials say that some people are trying to "engage in social unrest."
"Police officers have been heavily deployed to deal with any public disorder. The security roadblocks on our roads are there to monitor the situation," police spokeswoman Charity Charamba told a news conference in the capital.
"We have information and intelligence on the identities of some criminal elements that are behind the social unrest," she added.
Growing discontent against Mugabe
Despite President Mugabe's strict control on the country, public dissent against his 36-year-rule is increasing.
Last month, police arrested 15 people, including a journalist, during a public protest against the president.
Rights groups accuse Mugabe of repression and human rights abuses, whereas the opposition party, the Movement for Democratic Change (MDC), demands the 92-year-old president's resignation.
"The crisis is worsening every day and the deteriorating situation demands nothing less than resignation of President Robert Mugabe," MDC spokesman Obert Gutu told media on Monday.
"The situation in the cities, towns and villages points to a failed government," he added.
Monday's clashes come days after residents of the border town of Beitbridge protested against government restrictions on imports of basic goods from South Africa.
shs/kms (AFP, AP, Reuters)