(CNN) -- Three Chinese workers and their translator were kidnapped by guerrillas in southern Colombia this week, an official in the department of Caqueta said.
The kidnapping, blamed on the Revolutionary Armed Forces of Colombia, or FARC, happened Tuesday, but wasn't revealed publicly until Wednesday.
They were kidnapped on a rural highway, said the region's secretary of the interior, Edilberto Ramon Endo.
The four victims work for United Kingdom-based Emerald Energy, a subsidiary of Sinochem, a Chinese conglomerate, which deals primarily with petrochemicals, according to the company's website.
The FARC have been at war with the Colombian government since the 1960s.
The group was also behind the March kidnapping of 23 oil workers in eastern Colombia, government officials said. One of those victims remains in captivity.
Journalist Fernando Ramos contributed to this report for CNN.