Colombia has declared a nationwide "prison emergency" after a series of attacks on guards that has left one dead, the justice ministry said Monday.
The move comes after a prison guard was gunned down by two men on a motorcycle at the entrance to a prison in northern Cartagena on Saturday.
Other attacks have taken place in the southwestern Valle del Cauca department, where authorities reported several guards injured. Local media said they had been shot in an attack.
"We have just unanimously approved ... the declaration of a prison emergency" to boost security, Justice Minister Nestor Osuna told a press conference.
He said the measures were aimed at "protecting the lives and integrity of prison guards and completely eradication of the extortion and corruption" that comes from the prisons.
Prior to the wave of attacks, a prison guard's union had threatened to go on strike if measures were not taken.
"Threatening pamphlets were also found in different prisons," the ministry said in a separate statement.
Osuna said a special prosecutor would be assigned to investigate the murders of prison guards, and another to tackle prison extortion and corruption.
Colombia's prison crisis comes after neighboring Ecuador launched a major crackdown on narco gangs operating from the country's jails.
Colombia's overcrowded prison system houses more than 190,000 prisoners, according to official figures.