DHAKA—Hundreds of clothing factories in an industrial zone outside Dhaka were forced to close temporarily Monday as protests demanding higher minimum wages for garment workers turned violent.At least 50 people, including six policemen, were injured when garment factory workers clashed with police in and around Bangladesh's capital, police said. Police officers had to use tear gas to disperse thousands of protesters who were smashing vehicles and trying to damage factories.Traffic was disrupted in the city after protesting workers set fire to cars in the Tejgaon industrial area in the heart of Dhaka on Monday morning. Protesters attacked a police outpost in Joydevpur, an industrial area about 40 kilometers north of Dhaka, and stole its arms and ammunition, Kabir Hossain, a local chief of police said. "Four rifles were looted by workers along with more than one hundred bullets," he said. "We recovered the burnt rifles later, but the bullets are missing." Workers around Dhaka have been protesting for days, demanding higher pay. Labor leaders are calling on the government to raise the minimum wage to 8,000 takas a month (around $100), which is more than double the current minimum wage of 3,000 takas. The country's per-capita monthly income is $70.The government has formed a committee to decide on a new minimum wage after consultations with factory owners and workers. The committee is supposed to make a recommendation by December but workers don't want to wait that long. Around 500 factories in the Savar, Ashulia and Gazipur industrial areas had been forced to close due to the violence, said Abdul Mannan Kochi, senior vice president of Bangladesh Garment Manufacturers and Exporters Association."The factory owners will pay higher wages as they are set by the wage board," he said. "But the vandalism and arson must be stopped now or the industry will be destroyed."Kamal Uddin, owner of the Diganta Sweater factory close to the looted police outpost, said parts of his factory had been set on fire by marauding workers. "Several hundred people came and started throwing rocks at my factory this morning," he said. "We had already shut the factory down fearing violence but the mob broke down the gate and set fire to a guard post."He said the factories need more protection from the government after violence was sparked as a government official promised workers higher wages. Mr. Uddin blamed comments made by a government minister at a garment workers' rally in Dhaka on Saturday for the flare-up in violence. Shahjahan Khan, the country's minister for shipping, told a workers' rally that the minimum wage would be fixed at 8,000 takas, according to local television reports. Mr. Khan couldn't be reached to comment Monday.Labor leaders said the workers deserve higher wages. Babul Akhter, president of the Bangladesh Garment and Industrial Workers Federation, said the Bangladesh Garment Manufacturers and Exporters Association needs to sit down with labor representatives and find a solution. "The workers have made this into a multibillion-dollar industry and deserve better wages," he said. "But violence is not the answer."More than four million people, mostly women, work in Bangladesh's apparel industry, which supplies major Western brands such as H&M Hennes & Mauritz AB, Gap Inc., Wal-Mart Stores Inc., Tesco TSCO.LN +0.03%and Inditex SA. It is a key driver of the South Asian country's economic growth.The world's largest retailers have flocked to Bangladesh in recent years, attracted by cheap wages and an abundant supply of labor. The country's clothing exports topped $20 billion last year and some analysts had expected apparel exports to double by 2015.However deadly accidents—including the Rana Plaza collapse in April, which killed more than 1,000 people, and the Tazreen factory fire in November which killed more than 100—have forced factory owners and garment importers to work harder and spend more to ensure higher safety