HARARE, Zimbabwe (AFP) — Riot police in Zimbabwe fired tear gas, beat up protesters and blocked off the site of an opposition rally in Harare on Friday, the latest in a string of demonstrations to hit the country.

The rally — which was authorised by a court — was to demand electoral reforms before 2018 when 92-year-old President Robert Mugabe, who has ruled the southern African country for decades, will seek re-election.

An AFP correspondent saw armed police firing tear gas and water cannon at protesters gathered on the fringes of Harare’s central business district while waiting for the court ruling to allow the march to go ahead.

Demonstrators fought back by throwing stones at police while some set tyres ablaze and others pulled down the sign for a street named after Mugabe.

Some people caught up in the melee, including children going to an agricultural show nearby, ran for shelter in the magistrate’s court building while riot police pursued the demonstrators and threatened journalists covering the rally.

The usually bustling pavements were clear of street hawkers while some shops were shut and stones, sticks and burning tyres were strewn across the streets.

The opposition protesters also clashed with supporters of the ruling ZANU-PF party who had refused to clear their street stalls.

The ZANU-PF youths hurled stones at the opposition activists but were overpowered and their market stalls were set on fire.

High court judge Hlekani Mwayera ordered the police and government “not to interfere, obstruct or stop the march” organised by 18 opposition parties including the Movement for Democratic Change led by Morgan Tsvangirai and the Zimbabwe People First formed this year by former vice president Joice Mujuru.

“We view this as victory for democracy,” opposition spokesman Douglas Mwonzora said after the court ruling.

“The demonstration is going ahead (although) we know the police have already teargassed the venue.”

The move to seek court backing came a day after police violently put down another march by opposition youths, firing tear gas and water cannon and beating them as they staged a protest against police brutality.

Foreign diplomatic missions based in Harare called on the authorities to ensure that basic human rights and freedoms are respected during policing.

The Australian embassy said in a statement it “shares the concerns of many Zimbabweans at the violence which has occurred over recent weeks.”

“The use of violence is not acceptable under any circumstance,” it said.

The Canadian embassy also said it was “increasingly concerned with reports of violence and human rights violations in response to public protest”, and called for calm.

Police tried to “discourage” Friday’s march, saying the anticipated crowd of around 150,000 would disrupt business and traffic.

But the opposition was defiant and resorted to the courts for protection.

Former cabinet minister Didymus Mutasa, spokesman for the National Electoral Reform Agenda which groups political parties pushing for the reforms, said the march was to demand free and fair elections.

Zimbabwe’s last elections in 2013 were won by Mugabe in a vote the opposition said was rigged.

Home Affairs Minister Ignatious Chombo warned on Thursday that the government would clamp down heavily on what it termed “Western-sponsored” protests seeking “regime change”.

Zimbabwe has seen a mounting tide of violent protests over the past weeks, with demonstrators calling on Mugabe to step down.

Mugabe, who has been in power since 1980, has overseen an economic collapse that has caused food and cash shortages, with the country battling to pay public servants.