Security guards shot and wounded four people at a mine near Johannesburg early on Monday, police said, adding one is in serious condition. The shooting took place as a crowd of miners rallied at the gates of the mine belonging to Gold One International Limited, demanding to be re-employed with higher salaries, according to eye witnesses. The wounded miners, three with less serious injuries, were sent to a nearby hospital for treatment before police arrived at the scene, police spokesperson Captain Pinky Tsinyane said. Four people were arrested for allegedly inciting violence, Tsinyane said. Miners at the mine have been on strike since June 4 to demand a rise in salaries. Some of the striking miners were sacked by Gold One for taking part in the strike. Gold One, a mid-tier mining group with gold operations and gold and uranium prospects across Southern Africa, made no comment on the incident. Calls by Xinhua to the mine went unanswered. This was the second violent mine incident in less than one month along the mining belt near Johannesburg. In August, 44 people were killed in wage protests at the Lonmin Platinum Mine in Marikana in the North West Province in what was believed to be the worst mine violence since the end of apartheid in 1994. At the Lonmin incident, 34 people were shot dead by police, and 10 others, including two police officers, were killed in internal violence among miners belonging to two different unions. Monday's incident raised the specter of labor unrest spreading to other mines in South Africa.