By CHRISTOPHER TORCHIAJOHANNESBURG (AP) â¿¿ South African police fired rubber bullets at striking farm workers who set up barricades and threw stones at motorists and security forces on Wednesday in a province whose vineyards are vital to the wine industry. At least 50 demonstrators were arrested, authorities said. Labor unrest was reported in several areas of Western Cape province, where similar protests last year also turned violent, causing at least two deaths. Chaotic scenes unfolded in the town of Grabouw, where protesters, some carrying clubs, raced through the streets during clashes with riot police. One man taunted police by pointing a stick at them in the manner of someone lining up a rifle's sights. An injured female demonstrator grimaced as blood flowed down the side of her face. Dozens of protesters looted a supermarket in Grabouw and dispersed when police arrived and ran into the store, guns drawn, reported Eyewitness News, a South African media outlet. Footage on eNCA television showed debris in flames on a rock-strewn highway, and the smashed window of a police vehicle. Security forces in helmets patrolled the area. Police Lt. Col. Andre Traut said police had arrested about 50 people across the province, according to the South African Press Association, or SAPA. The protesters had sought to block roads in a campaign for higher wages and to prevent other farmhands from going to work. They want their daily wages to be more than doubled to 150 South African rand ($17.5), saying they can't survive on current salaries. Porchia Adams, a spokeswoman for Agri Wes-Cape, a farmers' group, said some workers had been coerced by protesters into staying away from their jobs. "They said they had been threatened that their houses would be burned down if they went to work, so it was not worth the risk for them," Adams told SAPA. "It is peak season, so we really cannot afford it. We hope this will be resolved soon."