The Colombian government on Friday blamed leftist ELN rebels for the car bomb that killed 21 people at a Bogota police cadet training academy, an attack that prompted fears of a return to the country’s violent past.
Defense Minister Guillermo Botero, speaking from the presidential palace, described the Thursday bombing as "a terrorist attack committed by the ELN".
Peace talks with the National Liberation Army, Colombia’s last major rebel group, broke down in August 2018.
Mr Botero said he had "full evidence" that the bomber – earlier identified as Jose Aldemar Rojas Rodriguez, 56 – has been a member of the ELN for more than 25 years.
According to Mr Botero, Rojas was known by his nickname "One-hand Kiko" for losing his left hand in a blast and was an intelligence chief in an ELN unit operating in the department of Arauca, on the border with Venezuela.
"This was an operation that has been planned for the past 10 months," Mr Botero said, stating that the guerrillas were the "intellectual authors" of the attack.
Initially after the attack, authorities said they identified the bomber but that he had no known links to armed guerrilla groups.
In Thursday’s attack, which the government described as an act of terrorism, the car broke through checkpoints into the grounds of the General Santander School before it detonated, shattering windows of apartments nearby.
President Ivan Duque called the explosion a "crazy terrorist act" against unarmed cadets and ordered police and the military to find the perpetrators and bring them to justice.
"We will not rest until we capture and bring to justice the terrorists involved," Mr Duque said late on Thursday. "I tell the criminals that social repudiation awaits them, the rejection of all Colombians and the international community."
The vehicle, a gray Nissan Patrol SUV, was carrying 80 kilogrammes (176 lb) of the high explosive pentolite, which has been used in the past by Colombian guerrillas.
Car bombs were frequent in Colombia during decades of civil war between the government and various leftist rebel groups, as well as in violence involving the Medellin drug cartel led by the late drug lord Pablo Escobar.
The worst of the war, which killed some 260,000 and left millions displaced, ended when the government reached a peace agreement with the Revolutionary Armed Forces of Colombia (FARC) in 2016.
The last major attack was in January 2018 when the biggest rebel group that remains active, the National Liberation Army (ELN), detonated a bomb in the northern port city of Barranquilla, killing five police officers and injuring dozens.
The ELN, made up of some 2,000 fighters and considered a terrorist organisation by the United States, has been in talks with the government since February 2017 to end the conflict. Mr Duque, who took office in August, has said conditions for peace talks included the ELN suspending hostilities and releasing all hostages.