Colombian authorities said FARC rebels are believed responsible for an ambush that killed four police officers and wounded three in the southwestern coastal town of Tumaco, AP reported. Gen. Orlando Pineda is the region's top police official. He told The Associated Press the officers were part of a 10-man patrol that was on its way to set up a road checkpoint when it was attacked late Wednesday morning. Hospital officials said the slain police had multiple bullet wounds. Southwestern Colombia has seen a recent uptick in attacks by the FARC, a leftist insurgency fighting the state for a half century. Colombia's Defense Ministry said at least 115 security force members have been killed in action so far this year. -- SPA