Three Chinese workers for the British oil company Emerald Energy have been taken hostage in southern Colombia, officials said Thursday, blaming the kidnapping on FARC guerillas. A fourth foreigner, who was working as a translator, was also taken hostage, said Edilberto Ramon Henido, secretary of the local government in southern Caqueta department, but he could not confirm the man\'s nationality. Citing sources in China\'s embassy in Bogota, the Xinhua news agency said all four men were Chinese workers for the oil company. The kidnapping took place as the employees were travelling in a car near the town of San Vicente de Caguan, Henido said, when a group of armed men blocked the road and took them hostage. At least seven gunmen dressed in civilian clothes carried out the assault, Colombian army general Javier Florez told RCN radio in Bogota, adding the workers were taken by their kidnappers into the mountains, and that troops had already begun searching for them. Their Colombian driver was set free after, said Henido, who blamed the kidnapping on leftist rebels from the Revolutionary Armed Forces of Colombia (FARC), South America\'s longest running insurgency. The FARC, which has been at war with the Colombian government since 1964, is the country\'s oldest and largest leftist group, with an estimated 8,000 combatants. Last year, 282 people were kidnapped in the South American country -- a 32 percent increase compared to the previous year, according to official figures. Criminals were responsible for most of the kidnappings -- 57 percent -- compared to 35 percent for leftist guerillas. Earlier this year, Colombian President Juan Manuel Santos warned multinational companies that they would be kicked out of the country if they paid ransoms to rebel groups or other criminal gangs that have kidnapped their employees. That warning, in March, came after more than 20 employees of South American Exploration, a subcontractor of Canadian oil company Talisman Energy and Colombia\'s Ecopetrol, were freed by their kidnappers, with Santos noting there was talk among the freed hostages of a ransom of some $2.6 million. \"They insinuated that that figure had already been agreed on with the company,\" Santos said at the time, noting that it was a criminal offense under Colombian law to pay off kidnappers with ransom payments.