Colombian President Gustavo Petro has suspended a ceasefire with a dissident Farc rebel group in the four regions where it is most active.
The suspension was triggered by the killing of four indigenous teenagers by the left-wing rebel group EMC-Farc.
It comes just two months after Mr Petro put on hold a ceasefire with another of Colombia’s armed groups, the Gulf Clan.
The president came to office in August of last year with the aim of achieving “total peace” in Colombia.
But on Monday Mr Petro released a statement in which he questioned the EMC-Farc’s commitment to the bilateral ceasefire it had agreed with the government following the “atrocious incident” in southern Colombia.
Opiac, an umbrella group representing indigenous groups in Colombia’s Amazon region, had been the first to denounce the murder of the four youngsters.
According to Opiac, the four, who are members of the Murui indigenous group, had been forcibly recruited by the left-wing rebels.
They managed to escape but were tracked down by their captors and shot in the head, Opiac said.
One indigenous human rights advocate, Carlos Garay Martínez, told local media that the four teenagers, who he said were aged between 14 and 16, had been “massacred in front of their community”.
Indigenous groups have borne the brunt of Colombia’s armed conflict.
Not only have they often been caught in the crossfire when the security forces and rebels group fight, but many of their children have been abducted or lured away to fight for these armed groups.
Colombia’s peace commissioner called the killing of the four “an attack on peace” and said the forced recruitment of children was a war crime.
The EMC-Farc is a off-shoot of the Revolutionary Armed Forces of Colombia (Farc). It is made up of left-wing rebels who refused to lay down their arms when the Farc leadership signed a peace deal in 2016.
The dissident group is thought to have around 3,000 members and while it is active in most of Colombia, its stronghold is in the provinces of Caquetá, Guaviare, Meta and Putumayo.
President Petro said that “all offensive operations” against the group would be reactivated in those four provinces within 72 hours.
It is the latest blow to his peace strategy which has already been hampered by the crumbling of the ceasefire with the Gulf Clan and the pulling out from peace talks by the rebels from the National Liberation Army.