The Canadian-Colombian oil firm Pacific Rubiales has threatened to shut down operations at its sizable Rubiales and Quifa fields following a series of attacks on its facilities. \"At the moment we are once again victims of violent attacks on our infrastructure. If this continues it will be necessary to shut down the field,\" company vice president Federico Restrepo said at a Tuesday press conference. He said unknown individuals had slipped in and set fire to workers\' quarters at the fields, which produce some 240,000 barrels of oil a day. \"Because of these acts of violence our people cannot leave the camp to take time off. They have technically kidnapped us,\" he said, calling on authorities to increase security and arrest those responsible for the attacks. Regional authorities said the attack was linked to a protest Monday by some 4,000 employees demanding higher wages and improved working conditions. The company faced large protests last month in which workers and local residents burned tents and destroyed other equipment, forcing the company to temporarily shut down the oil fields. It reached an agreement earlier this month to hire unskilled labors locally, but is still in negotiations with employees. Colombia produced 953,000 barrels of oil per day in August, a rise of more than 20 percent over the past year. The Rubiales and Quifa fields account for around 20 percent of total production. The center-right government of President Juan Manuel Santos sees the oil industry as a key driver of economic growth and is aiming to raise crude output to 1.15 million barrels a day by the end of his term in 2014. Colombia is the third-largest oil producer in South America after Venezuela and Brazil.