Colombian president Gustavo Petro is warning that his nation's military will take offensive actions against the National Liberation Army after the rebels, known as the ELN, unleashed a wave of attacks in the country's northeast that left dozens of people killed and forced thousands to flee their homes.

Colombia vowed "war" against left-wing guerrillas Monday, as security forces rushed to contain a wave of violence that has killed more than 100 people and threatens to derail the country's

The unusually deadly violence delivers a devastating blow to the “total peace” program of the country’s first leftist president, Gustavo Petro.