New Delhi, June 8 -- Colombian President Gustavo Petro has vowed to leave no stone unturned in identifying those behind the attempted assassination of opposition senator and potential presidential contender Miguel Uribe. The 39-year-old conservative lawmaker was shot during a campaign event in Bogota on Saturday and remains in critical condition.

"No resource should be spared-not a single peso or a single moment of energy-to find the mastermind. whether in Colombia or abroad," Petro said in a televised address. He condemned the attack and called for an independent investigation to identify the "intellectual authors" behind the shooting.

Authorities confirmed that a minor under the age of 15 was arrested at the scene carrying a Glock 9mm...