Colombian officials say leftist rebels have attacked a military convoy in remote northeastern Colombia, killing six soldiers and 10 security officers.
The attack Thursday took place near the town of Hacari in Norte de Santander province, which borders Venezuela.
The Colombian military says it and the Department of Administrative Security (DAS) were carrying out operations against the country's largest rebel group, the Revolutionary Armed Forces of Colombia (FARC) when explosives were detonated alongside their convoy.
Violence has increased ahead of the May 28 election, in which anti-crime President Alvaro Uribe, is expected to win re-election.
Human Rights Watch has accused FARC of massacring dozens of civilians, including children in an effort to intimidate voters.