Colombia's largest left-wing rebel group unexpectedly released four hostages, El Tiempo reports.

The hostages -- held by the Revolutionary Armed Forces of Colombia, or FARC, for more than three years -- were released from their jungle prison and flown to freedom abroad a military plane.

The release follows last week's proposal by Colombian President Alvaro Uribe to swap prisoners with the FARC, though it remains unclear if the release was part of that deal.

The Colombian president first made a prisoner exchange offer with the FARC in August, to which the group replied a month later requesting Uribe demilitarize a large southern region of the country.

Uribe rejected the idea, stressing Colombia "will not suspend military actions in any part of our national territory."

Colombia has been battling leftist rebel groups like the FARC for the last 40 years.