Zimbabwe faces a new wave of unrest as the group representing government workers announced on Wednesday that civil servants across the country will go on strike after salary negotiations failed.David Dzatsunga, secretary of the Civil Service Apex Council, said the strike will begin on Friday as the southern African nation's economic collapse deepens and frustration with President Emmerson Mnangagwa's government grows.A crackdown on last week's protests over a sharp rise in fuel prices continued in the courts and on the streets, where witnesses and rights groups reported abuses by the military, police and ruling party youth gangs. Mnangagwa's call for national dialogue has been met with skepticism.A labour federation leader charged with subversion appeared in court along with dozens of others accused of involvement in the protests, while their lawyers accused the government of systematically denying them justice.Japhet Moyo, secretary-general of the Zimbabwe Congress of Trade Unions, could face 20 years in prison. He is accused of inciting Zimbabweans to protest the fuel price increase by staying off the streets. Other Zimbabweans, frustrated over the long lines for fuel and other basics, demonstrated, with some looting shops in anger or desperation.The military deployed, and doctors and rights groups have documented at least 12 people killed and more than 300 wounded. Some were shot at close range. Others were pulled from hospital beds and arrested.They are likely "just a fraction of the actual victims," the Zimbabwe Association of Doctors for Human Rights said on Tuesday.Labour leader Moyo has pleaded not guilty. Pastor and activist Evan Mawarire, also accused of subversion for joining Moyo's call for protest, had his application for bail delayed until Friday by the High Court in the capital, Harare. He has been detained for a week.Lawyers say more than 600 people have been arrested, with most of them denied bail. Those arrested, killed and wounded include ordinary citizens, including children. Some hungry Zimbabweans were picked up after venturing out in search of bread or other basics from the few shops open during the protests.The dozens in court on Wednesday are accused of "committing public violence."Lawyer Beatrice Mtetwa alleged "a coordinated, deliberate orchestrated attempt to subvert justice." Some people were forced to stand trial without being given sufficient time to brief their lawyers, she said."We have had a pattern ... of every magistrate in different provinces doing exactly the same thing," said Mtetwa, a board member of Zimbabwe Lawyers for Human Rights.Responding to the president's call for national dialogue, main opposition leader Nelson Chamisa on Tuesday called for the "unconditional release of all prisoners of conscience and political detainees."In Harare's city centre and in many of its working-class and poor suburbs, armed soldiers maintained a presence and at times beat up people, according to residents, non-governmental groups and the opposition.Zimbabwe's government has provided buses with cheaper fares, and accompanied by armed soldiers, to ferry people to work. There were long lines for cooking gas and other basic items, and people elbowed each other for bread in shops that still had it in stock.Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.