The attack disrupted electricity supply in parts of Alvarado and adjacent regions, said Colonel Julio Santoyo, a military commander.Explosive devices were placed in the towers by the Revolutionary Armed Forces of Colombia (FARC), the largest rebel group in Colombia, Santoyo said.There have been no comments from the FARC about the attack.The FARC, with an assumed 17,000-strong members, has been fighting government forces since it was founded in 1964.The government troops have launched several attacks against the FARC from the beginning of this year. (Xinhua)