As protesters brought the centre of Zimbabwe's capital to a standstill and fought running battles with police on Friday in one of the biggest demonstrations for decades against President Robert Mugabe, more of the same has been promised. The chaotic scenes in Harare came after 18 opposition groups and parties called on their supporters to march for reform of the widely discredited electoral system before national elections in 2018.The authorities had tried to block the protest, but the high court gave it the go-ahead. Even so, police used teargas and water cannon against marchers in Freedom Square within 20 minutes of the court order being made.Mugabe warned protesters that there would be no "Arab Spring" in Zimbabwe.story_article_left1"They are thinking that what happened in the Arab Spring is going to happen in this country, but we tell them that it is not going to happen here," he said, referring to uprisings that toppled leaders across the Arab world.Mugabe accused Western countries, including the US, of sponsoring the protests. "They are fighting because of Americans," he said.Douglas Mwonzora, the opposition Movement for Democratic Change secretary-general, said the regime should expect no peace in coming weeks.Brighton Chavanduka, 45, an unemployed father of four, said he had been sacked from his secretarial job six years ago because of his support for the MDC. "They hate this today because the opposition is getting together. We will be stronger together," he said.Home Affairs Minister Ignatius Chombo labelled opposition leaders "foreign agents" and accused them of using protests to cause chaos in order to justify international intervention . "Those regime change agents bent on trying to remove a democratically elected government will face the full wrath of the law."Earlier, MDC head Morgan Tsvangirai and former vice-president Joice Mujuru fled a rally in their cars while protesters ran for cover as police broke up the core of the demonstration.However, anti-Mugabe leaders warned that this would be the first of a series of protests.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.block_quotes_start Today has been for me the worst day that I have lived in this country, where I have observed with my own eyes the state breaking its own laws block_quotes_endClashes spread through the streets of Harare as riot police fought running battles with protesters who hurled rocks at them, set tyres ablaze and burnt a popular market to the ground, in some of the worst unrest since food riots in 1998.Didymus Mutasa, a senior official from Mujuru's party and convener of Friday's protest, vowed to repeat the demonstration and blamed police for the violence and disobeying a court order."If that was intended to cow us from demonstrating, I want to say the opposite has been the case. We are going, next Friday, to do exactly the same as we have done today."Most businesses closed early on Friday, fearing looting.Mujuru said 50 people were injured and admitted to hospital."Mugabe's rule must end now, that old man has failed us," said one protester before throwing a rock at a taxi.full_story_image_hleft1More than a hundred police officers in riot gear, backed up by water cannon and armoured trucks, occupied the venue for the demonstration.As opposition supporters arrived, police told them to leave. The police fired teargas and water cannon when some in the crowd refused to comply.Police spokeswoman Charity Charamba said the day's events were still being assessed.Officials from Mugabe's ruling Zanu-PF party were not available for comment."Demonstrating is the only solution left to force the dictator out of office," said Tapfuma Make, a jobless 24-year-old.story_article_right2The high court ruled that police should allow the protest to proceed between noon and 4pm in what the MDC called a "victory for democracy".Mutasa said: "Today has been for me the worst day that I have lived in this country, where I have observed with my own eyes the state breaking its own laws and the state starting violence by attacking people who were just gathered together."Opposition parties leading the protests say the electoral commission is biased in favour of the ruling party and is run by security agents loyal to Mugabe, charges the commission denies.The protesters want the next election, in 2018, to be supervised by international observers, including the UN. They are also calling for Mugabe to fire corrupt ministers, scrap plans to introduce local banknotes and end cash shortages.The latest unrest comes nearly two months after the biggest "stay at home" strike in Zimbabwe since 2007, inspired by social media movements such as #ThisFlag, led by pastor Evan Mawarire...