Leftist Colombian rebels have killed a total of 28 people in recent days, Colombian officials said Monday. Also Monday, FARC said in a message that it would insist on an exchange of hostages with the Colombian government after releasing six hostages last week. The Awa indigenous people reported that at least 20 members of their tribe had been killed by the Revolutionary Armed Forces of Colombia (FARC) in two different villages, Antonio Navarro, governor of the south-western province of Narino, said on Monday. In a separate incident, six soldiers were killed and four were injured Monday in south-western Colombia in an attack that was allegedly perpetrated by leftist rebels, according to media reports in Bogota, quoted by DPA. The network Caracol said the incident happened near the town of Morales, in the province of Cauca, when the military officers were on patrol. Reports did not give details as to whether the soldiers entered a minefield or were ambushed by FARC.