The families of victims thought to be kidnapped by members of the Revolutionary Armed Forces of Colombia - or FARC - demonstrate in Bogota's Bolivar Square on Thursday.
Displaying photographs of their missing relatives, they blamed the leftist rebels - saying they want answers - as peace talks between the government and rebel negotiators took place in Oslo.
Teresa Duque de Silva said FARC rebels kidnapped her son in 2002.
SOUNDBITE: Teresa Duque de Silva, Victim's mother (Spanish)
"Tell them to tell us the truth. Nothing but the truth. I am resigned, we are resigned to receiving the news, no matter how severe, to find out if they killed him."
The Norway talks represent the latest attempt in a decade to broker peace with the rebels.
As preliminary talks wrapped up, both sides agreed to meet in Cuba next month - to continue negotiations.
