Colombia’s anti-government guerrillas have grown stronger under President Gustavo Petro’s three years in office.

At least 18 people have been killed and dozens wounded in two separate attacks in Colombia, deepening the country's most serious security crisis in decades. Six people died and more than 60 were injured after a car bomb exploded on a busy street in the western city of Cali in Colombia, according to authorities.

An attack on a Colombian National Police helicopter and a suspected car bombing near a military air base left at least 19 people dead Thursday in what Colombian authorities are describing as terrorist acts.