Police in Colombia are hunting for more than a dozen prisoners after a mass jail break in Tumaco, in southwestern Narino province.
Some 20 inmates escaped from Buchely jail after an explosion at the prison.
Three have been recaptured, officials said.
Narino police commander Col William Montezuma said the fugitives were dangerous and included at least one senior member of the left-wing Farc rebel movement.
He is believed to be the commander of the 29th front of the Farc, which is active in Narino.
Another is a man accused of running the finances of a local Farc commando.
An explosive device, believed to have been planted by Farc rebels on the outside, blew a hole in the perimeter wall of the prison just after midnight local time, prison authorities said.
In the confusion which followed, some 20 prisoners escaped, of which three were quickly recaptured.
Prison officials said the quick reaction of the guards prevented any more of the remaining inmates, numbering about 270, from escaping.
Explosive experts spent hours defusing a second device which the fugitives planted on the main road leading from Tumaco to Pasto. The road was closed for 11 hours.
Police, army and navy are combing the dense jungle and waterways around Tumaco.
The security forces fear the fugitives may be trying to escape to Ecuador, which lies just south of the city.
Farc rebels are known to have taken refuge in Ecuador in the past.
A Colombian bombing raid on a rebel camp there in 2008, in which Farc commander Raul Reyes was killed, led to a breakdown in relations between the two countries which lasted for two years.