At least ten Colombian soldiers were killed and six wounded in a pre-dawn attack on an army patrol with homemade explosives by the country's second-largest leftist rebel band, the military said.
The 2.00 AM attack by the National Liberation Army, or ELN, occurred in a rural area of Chitaga in the northeastern state of Norte de Santander, said the regional divisional commander, Gen Juan Pablo Amaya.
He said two of the wounded were in critical condition and one soldier was missing and presumed captured by the rebels.
It was the biggest blow to Colombia's military since February, when seven soldiers died in combat with the larger rebel movement, the Revolutionary Armed Forces of Colombia, or FARC, and came on the eve of a regional trade summit in the western city of Cali that the leaders of Peru, Chile, Costa Rica, Guatemala, Mexico, Spain and Canada were expected to attend.
Amaya said the 32-man patrol was attacked while in a fixed position with sentries posted. He would not offer any other details, such as whether any of the soldiers were sleeping at the time.
Amaya said the men were out on a routine patrol. Santos' government has been in peace talks with the FARC for the past six months in Cuba, and they are currently stalled on the first agenda item: land reform. The ELN, whose strength the Defense Ministry estimates at 2,000-3,000 fighters, is not involved but seeking similar negotiations.
The ELN kidnapped a Canadian mining executive, Gernot Wober of Toronto-based Braeval Mining Corp, in January in a state adjoining Norte de Santander.
It said earlier this month that it will not release Wober until his company turns over the title to its gold mining concessions in Norosi, in the San Lucas mountain range, to local communities, which the rebels say are the rightful owners.
Santos says there will be no talks with the ELN until the 47-year-old Wober, the company's vice president of exploration, is freed unconditionally.
Both the ELN and the FARC emerged in the 1960s, largely as an outgrowth of rural peasant movements seeking a more equitable distribution of Colombia's agricultural lands.
Also yesterday, the FARC denied any involvement in the ransom kidnapping of a pair of Spanish tourists in Colombia's northeastern state of La Guajira.
