More than 500 miners who stayed underground for almost three days in a standoff between rival South African labour unions were all brought back to the surface on Wednesday, police said.Some 455 workers including paramedics and security guards emerged into the afternoon daylight after a first group of 107 had made their way back up in the morning, said police spokeswoman Brenda Muridili.”The mine rescue team has confirmed that they have cleared the underground area,” she said. “Paramedics that were on the surface provided medical assistance and four injured men, including a security officer, were taken to hospital for further medical treatment,” she added. Authorities seized sticks and screw drivers that were found in the mine lift and would open a case of kidnapping and assault, she said. The miners had failed to emerge from the Gold One mine in Springs, east of Johannesburg, after a night shift on Monday.The National Union of Mineworkers (NUM), one of the two unions involved, and management at the mine said the workers were being “held hostage” by members of the rival Association of Mineworkers and Construction Union (AMCU).AMCU denied the allegations, saying the miners were staging a “sit-in” protest. But police later said that some miners confirmed in interviews with detectives “that they were indeed held against their will”.NUM’s spokesman Livhuwani Mammburu said some of those who got out in the morning did so after overpowering “those that were holding them hostage”. – AMCU seeks recognition -The AMCU’s regional secretary Tladi Mokwena had earlier said that all the miners were coming out “willingly” having run out of food. “Management has closed all the routes for them to receive food. So, we couldn’t allow workers to stay underground without food,” he said. The dispute revolved around union representation at the mine, where the NUM is currently the only group officially registered.The AMCU says an overwhelming majority of miners have signed up to join it. But it is yet to be given official representation, which it says is the reason for the protest. The NUM was founded in 1982 by the country’s President Cyril Ramaphosa, a former labour unionist. It remains the nation’s biggest mineworker union.