South African police have fired rubber bullets and water cannon at crowds of striking civil servants protesting outside a hospital in Soweto. More than a million public workers began an indefinite strike on Wednesday calling for higher wages. More unions have joined in on the second day of industrial action. Meanwhile, health authorities in Gauteng say army medics have been brought in to help in some hospitals because of staff shortages. The province's health minister said they were also investigating whether the deaths overnight of five people in a hospital east of Johannesburg were linked to staff shortages because of the strike. Unions affiliated with Cosatu, South Africa's main union federation, have been holding out for an 8.6% pay rise. But South Africa's government says it can barely afford the 7% offer it has put on the table for the police, teachers, doctors and nurses. Helicopter hovering When rowdy strikers in Soweto stopped patients from entering the hospital grounds on Thursday morning, the police - forbidden by law from joining the strike - moved in. Police spokeswoman Captain Nondumiso Mpantsha said the protesters were also trying to force their way into picket inside the Chris Hani Baragwanath Hospital. "Police had to use minimum force and fire rubber bullets to disperse the crowd," she told the BBC. "The situation is under control now because there is a heavy police presence at the scene." Meanwhile, Johannesburg's Eyewitness news website is reporting that a police helicopter is flying over the city's main Helen Joseph Hospital monitoring protests there. The unions say they are also planning to shut down one of the busiest motorways in Johannesburg on Thursday. Teachers have threatened to disrupt classes at private schools. Source: BBC