Eight rebel fighters surrendered Saturday to soldiers in northwestern Colombia as the army tightened its hold on the region, authorities said.

The government of President Alvaro Uribe is offering a temporary salary and job training to encourage rebels to lay down arms and end Colombia's 38-year civil war. Defense Minister Martha Lucia Ramirez has said the government is seeking to convince 6,000 of the country's approximately 21,000 leftist insurgents to surrender this year.

Seven men and a woman from the leftist National Liberation Army, or ELN, turned themselves over to an army patrol in Cocorna, 120 miles northwest of Bogota in Antioquia province, said Gen. Mario Montoya, commander of the army's 4th Brigade.

One of the rebel deserters, Elias Gonzalo, told reporters that more of his comrades were planning to surrender soon.

Also Saturday, a motorcycle rider threw a grenade at police officers patrolling the town of Saravena in violent northeastern Arauca state, injuring nine civilians. The government blamed the main rebel group, the leftist Revolutionary Armed Forces of Colombia, or FARC.