Colombian president Gustavo Petro warned on Monday 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.

The measure will go into effect after a decree is signed by the president and his Cabinet, but it can also be invalidated by Colombia's constitutional court. Internal commotion decrees were used in the early 2000s by the administration of then-President Álvaro Uribe to increase financing for the military through a special war tax.

Colombia has suspended peace talks with the National Liberation Army, or ELN, for second time in less than a year after blaming the rebel group for violence that has been affecting a northeastern region of the country in recent days.