BOGOTA, Colombia (AP) — Colombia's army says that an attack by leftist rebels along the South American country's volatile eastern border with Venezuela has left at least five soldiers dead and another 10 wounded.

The army said that the attack took place early Tuesday when a homemade explosive ripped apart a passing truck carrying the soldiers near the rural town of Tibu.

The army attributed the attack to the National Liberation Army, the largest remaining rebel movement following a peace deal in 2016 with the much-larger Revolutionary Armed Forces of Colombia.

The ELN, as the group is known, announced Monday it would unilaterally suspend all offensive operations March 9 in time for congressional elections.

Long-running peace talks with the ELN have been faltering this year as the rebels step up attacks across Colombia.