Guerrilla forces believed to be behind bomb GRANADA HILLS, Colombia, June 20 (UPI) -- Colombian police blame the Revolutionary Armed Forces of Colombia for a bombing in Granada Hills that injured eight police officers and several civilians. The guerrilla group, also known by its Spanish acronym FARC, is believed to have detonated a bomb near a police truck in the area around 1 p.m. Tuesday, spraying shrapnel onto officers and bystanders. One officer is in critical condition, said Colombia Reports. Several nearby houses were also damaged in the blast. Explosives experts scoured the area for other hidden bombs, the report said. FARC launched a grenade at an army checkpoint in Buenaventura Monday, injuring one soldier and eight civilians.