The FARC guerrilla group for the first time accepted partial responsibility Tuesday for the thousands of victims of Colombia's nearly 50-year-old insurgency.
The statement was read out by a top FARC negotiator on the sidelines of peace negotiations in Havana between the leftist rebel group and the government of President Juan Manuel Santos.
"Without a doubt, there has also been cruelty and pain provoked by our forces," said the negotiator, Pablo Catatumbo.
The acknowledgement that the FARC bears partial responsibility for the bloodshed comes nearly a month after Santos publicly admitted that the Colombian state was responsible for "serious violations" of human rights during the conflict.
Taken together, the statements appeared to mark a significant step forward in the peace process, which has been underway since November.
Some 220,000 people, most of them civilians, are estimated to have died in Latin America's oldest armed conflict.