On Saturday, Defense Minister Luis Carlos Villegas, said Colombia's army had launched a retaliatory attack on the National Liberation Army (ELN) after the left-wing guerrilla group blew up a bridge in Cesar Department in the north and attacked a truck using an explosive device, RCN Radio reported. 

The ELN bomb caused a 150-car pileup, said General Jorge Hernando Nieto, the director of the national police force, adding that no injuries had been reported.

"The operations of the public force against the ELN and the security devices for the national roads are already underway," Villegas said.

The guerrillas said the offensive would last from Saturday until Tuesday.

Talks broke down

President Juan Manuel Santos suspended the peace talks on January 29 for an indefinite period after the rebel group carried out a series of attacks against police, leaving seven officers dead and 40 injured.

The ELN, with an estimated 2,000 fighters, is Colombia's last active guerrilla group, after the FARC signed a peace deal with the government in November 2016.

The agreement followed five decades of conflict involving leftist rebel movements, the army and right-wing paramilitary groups, in which 260,000 people were killed and 7 million people displaced.

The Catholic Church and UN officials also insist that the government should re-engage in the ceasefire talks.

jbh/bw (dpa, Reuters)