More than a hundred police officers in riot gear, backed up by water cannons and armoured trucks, occupied the venue that opposition parties planned to use for their march.

Mugabe’s opponents have become emboldened by rising public anger and protests over an economic meltdown, cash shortages and high unemployment. Mugabe, 92, has led Zimbabwe since independence from Britain in 1980.

As opposition supporters arrived for the march, they were told by the police to leave. The officers then fired teargas and water cannon when parts of the crowd refused to comply, a Reuters witness reported.

A few dozen supporters, who earlier chanted anti-Mugabe slogans, threw rocks at the police and burned tyres on the roadside near the square where the protest was due to start.

“We are not going anywhere and demonstrating is the only solution left to force the dictator out of office,” said Tapfuma Make, an unemployed 24-year-old from Chitungwiza town, south of the capital Harare.

Zimbabwe’s High Court ruled that police should allow the protest to proceed between 12 p.m. – 4 p.m. (1000-1400 GMT).

“We view this as a victory for democracy. The demonstration is going ahead,” MDC secretary general Douglas Mwonzora told reporters following the court’s decision.

Opposition parties leading the protests say the electoral commission is biased in favour of the ruling ZANU-PF and is run by security agencies loyal to Mugabe, charges the commission denies.

The protesters want the next vote in 2018 to be supervised by international observers, including the United Nations. They are also calling for Mugabe to fire corrupt ministers, scrap plans to introduce local bank notes and end cash shortages.

Opposition leader and head of the Movement for Democratic Change (MDC), Morgan Tsvangirai, and former vice president Joice Mujuru will lead the demonstration, which they expect to draw thousands of supporters.

Zimbabwe’s police used teargas and a water cannon on Wednesday to break-up a march by MDC youth supporters who were protesting over economic mismanagement and what they say is brutality by security agencies.