The regional headquarters of Colombia's biggest union CUT and offices of several NGOs were attacked with explosives in the east of Colombia. Nobody was injured.
The bomb attacks took place in Arauca, capital of the Arauca department and in the nearby town of Saravena.
The bomb, set off by "unknown individuals", caused "severe damage" to the outside of the union headquarters, CUT chairman Tarsicio Mora told Spanish Press Agency Efe.
The second bomb exploded in a building that houses the offices of several women's, farmers and indigenous rights groups.
The CUT chairman condemned "these type of actions that infringe the freedom of association and free expression of Colombian labor unions." Mora called for national and international solidaity with his movement.
The attack comes less than a day after the CUT accused Colombian President Álvaro Uribe of implementing policies that are "bad for unions", saying that 97% of the 474 murders committed on unionists were left unpunished.
