The President of Colombia Ivan Duque on Sunday took part in a march against a terrorist attack that took 21 lives in Bogota on Thursday.
The huge crowd marched to Bogota's iconic Plaza Bolivar while chanting slogans such as "down with the terrorists" and "no more violence".
They were wearing white clothes and waving white flags.
Dozens were also injured in Thursday's attack on General Santander Police Academy in the capital Bogota before a graduation ceremony.
Duque called it an "insane terrorist act" and declared three days of national mourning.
The terrorist attack was the deadliest in 15 years in Colombia.