In a statement released Sunday in Cuba, the group said it had been in "full compliance" with its self-declared truce, Colombia Reports said.
FARC -- Fuerzas Armadas Revolucionarias de Colombia -- has been in formal negotiations with Colombian authorities since Nov. 19 in Havana.
An army commander charged last week that two rebel troops with white banners lured government forces into a field in southeastern Colombia Nov. 20. Mines buried in the field were detonated, but no one was hurt.
The FARC delegation said "no combat unit of [FARC] or the Bolivarian militias operated in that area" on that day.
It called the charges "a dangerous pantomime of the army" aimed at discrediting the rebel group.
The formal talks to end a five-decade conflict cap six months of secret and informal talks between FARC and the government.