Five soldiers were killed and eight were wounded in a booby trap explosion while searching for rebel weapons in a remote region of central Colombia, local media reported.
The explosion occurred during a routine patrol near Vista Hermosa, in central Meta department by members of the Army's elite Omega unit tasked with tracking the leftist Revolutionary Armed Forces of Colombia (FARC) rebel group, a radio station said on Friday.
On Monday, four soldiers were killed in a FARC attack in southwestern Cauca department.
The FARC have stepped up attacks on the Colombian military and others lately, despite having released several of their prominent hostages earlier this year.
Negotiations for a prisoner swap of rebel hostages for rebels jailed in Colombia have stalled over President Alvaro Uribe's refusal to grant the rebel group a wide swath of demilitarised territory they are demanding for the talks to resume.
The rebels are holding hundreds of hostages, including 22 military and police that they are seeking to swap for some 500 guerrillas held in Colombian and US jails.