(adds expected talks, communist party member) By Felix Bate and Muchena Zigomo JOHANNESBURG, June 1 (Reuters) - South African civil servants staged an indefinite nationwide strike over pay on Friday, causing turmoil in hospitals and emptying classrooms in a mass action the government fears could hurt the economy. Police fired stun grenades at picketing workers outside Cape Town's Tygerberg Hospital, injuring at least one person, as many nurses across the country defied a government ban on job stayaways by essential workers, the SABC reported. South Africa's economy -- the continent's biggest - is booming but civil servants complain they haven't had a pay rise since one that ended a major public service strike in 2004. President Thabo Mbeki's government, fearing that significant wage increases could further raise inflation, has only offered half of the 12 percent rise demanded by unions. Anger boiled over after an official body recently recommended Mbeki receive a 57 percent pay rise. "Fifty-seven percent for fat cats and 6 percent for poor hard workers. Shame on you," one placard brandished by a picketer at the Johannesburg hospital said. COSATU, a crucial part of a formal alliance with Mbeki's ruling African National Congress, is increasingly frustrated over policies it says favour big business over the poor. Mbeki's free-market economic policies have been praised by foreign investors and have created a black middle class, but there are still stark inequalities left by apartheid. Raising the possibility that mass action could hit South Africa's vital minerals industry, COSATU's president urged miners to join the strike. "We are not going back until the government starts negotiating properly," Willie Madishi told civil servants outside the Gauteng province premier's office. MONDAY TALKS The government increased its offer on Wednesday to a 6.5 percent to 9.0 percent increase, but no breakthrough is in site. A joint committee aiming to break the deadlock over wages is expected to resume talks between the two sides on Monday, SAPA reported. But workers said they would not back down. "We have not closed or come close to closing the apartheid wage gap in the public sector," said Blade Nzimande, a member of the South African Communist Party (SACP), who joined the protest. The party is in the alliance with COSATU and the ANC. COSATU, which represents about 60 percent of the nation's nearly one million public servants, had aimed to shut down most public services in the wage dispute with government. It had called on 700,000 public workers to strike and said early turnout was a success. "Reports so far indicate a very, very good turnout," said COSATU spokesman Patrick Craven. But in some areas of the country teachers and nurses showed up for work as normal, making the impact hard to gauge. Authorities had also issued a reminder to essential workers such as firemen, police officers and doctors that they were barred from striking and a court order banned immigration officers from joining the action. COSATU issued a tough statement attacking police for what it called violent attempts to end the strike. "It is all the more shocking that the attacks were allegedly perpetrated by police officers whose unions are fully involved in the strike," it said in a statement. But hospitals appeared particularly hard hit, with nurses and cleaners picketing in Johannesburg and Cape Town over salary levels which see some nurses earning $640 per month. That is enough to rent a low cost, one-bedroom apartment. While schools were open in some parts of the country, in many other areas teachers and students failed to show up. "There is absolutely no teaching going on," said Principal Toyer Arnold of the Belgravia High School on the Cape Flats outside of Cape Town, where 80 percent of staff stayed away. (additional reporting by Eric Onstad in Johannesburg, Wendell Roelf in Cape Town)
