At least 15 people were killed over the last two days in Colombia in a spate of violent incidents, authorities said, highlighting the huge task facing President Gustavo Petro.
In the northern city of Barranquilla, six people were shot dead by gunmen on Monday morning while drinking in a bar.
Police said the powerful Gulf Clan drug trafficking gang carried out the attack on members of the rival Los Costenos group.
In the north-central Santander department, a teacher, his wife and two children were killed by a group of assailants on Sunday morning, local authorities there said.
Five Venezuelan migrants, accused of being involved in the murders, were then lynched by vigilantes in an apparent act of revenge.
The local mayor had told a national radio station that the murderers were "people from Venezuela" who wanted "to steal money" and used knives to kill their victims.
Following the attack, an injured employee of the murdered family alerted neighbors, who "took justice into their own hands and killed" the five attackers, said the mayor.
On Saturday night, a union leader was shot dead by two armed motorcyclists in the northeastern port city of Barrancabermeja.
According to the Indepaz NGO, it was the 126th murder of a union leader since the state signed a 2016 peace deal with Marxist Revolutionary Armed Forces of Colombia guerrillas.
Petro, Colombia's first left-wing president, vowed following his June election victory to bring about "total peace" in the conflict-ravaged country.
Colombia has suffered six decades of conflict involving leftist guerrillas, drug traffickers, right-wing paramilitaries and state forces.
A former urban guerrilla himself, Petro has vowed to open talks with the country's last recognized rebel group, the National Liberation Army (ELN).
He has also said he would seek dialogue with drug traffickers in a bid to end the cycle of violence.