Chechen rebels opened fire at a column of federal troops' trucks in Argun, at the crossing of the Gudermesskaya and Zavodskaya streets, a Chechen police official has told RIA Novosti. Ten rebels were killed by return fire. Several federal soldiers were injured. In another incident in Argun, on the Saikhanov Street, rebels opened fire from small arms at a group of police officers who were conducting an operation to detect and destroy mini-oil refineries which operated illegally. In all, Chechen rebels opened fire at federal troops seven times on Tuesday.