The attack took place near a local government headquarters in the western municipality of Pradera, Mayor Adolfo Leon told the RCN radio station, noting that "of the 25 wounded, six are critical."
He said the FARC was responsible.
The motorcycle had been loaded with explosives and placed in front of the building. The payload was then detonated, according to Leon.
Yesterday, the FARC ended a month-long holiday season truce that had been a gesture of goodwill during the peace talks with the Colombian government that are taking place in Havana.