In Caqueta, and the adjacent province of Meta, the rebels once controlled 42,000 square kilometers of demilitarized territory, granted as a condition for peace talks in 1999, which later failed. It is also likely to be the area where the most highly-trained, ideological rebels choose to hold out, if a peace agreement with the government is ever reached.

Like Meta, once a stronghold of the Revolutionary Armed Forces of Colombia (FARC) and now a mecca for Colombia's oil industry, Caqueta is attracting increased interest from oil multinationals. The rebels' extortion of and threats against oil subcontractors is nothing new, and has been seen since the days of the Arauca operations of British Petroleum, which was among the first foreign companies to initiate oil exploration on Colombian ground.

But the FARC's pressuring of oil subcontractors in Caqueta has taken a particularly ugly turn this summer. The rebels' extortion-related attacks against subcontractors usually consist of burning vehicles, attacking oil pipelines or kidnapping employees.

Recently, however, in Caqueta the FARC have begun using the same guerrilla-style attacks against oil subcontractors that are usually reserved for the security forces. These attacks, most of them involving the use of improvised explosive devices (IEDs) have actually resulted in civilian deaths, which is unusually aggressive for the FARC's offensives against oil multinationals. The Teofilo Forero Column, an elite unit, has been blamed for carrying out most of the assaults.

On September 17, a FARC unit ambushed an oil convoy of 15 trucks, using sniper and machine gun fire. One truck driver was killed. Two days later, FARC guerrillas ambushed a convoy of five oil trucks travelling between San Vicente del Caguan (once the heartland of the demilitarized zone) and Puerto Rico, leaving another civilian dead.

These attacks are clear imitations of three similar incidents in August. Over several weeks, the FARC killed another driver with a road bomb, burned a caravan of 16 vehicles, and killed another truck driver with sniper fire.

The attacks all took place in the Caqueta municipality of San Vicente del Caquan. Most appeared to be concentrated against subcontractors working for Emerald Energy, who saw three Chinese workers and their translator kidnapped last June. This appears to suggest that the unusually aggressive attacks are intended, in part, to pressue Emerald Energy into paying the ransom for the hostages.

InSight Crime has mapped the locations of the FARC fronts currently based in Caqueta.