A 4-year-old girl was killed and four other children, all siblings and cousins of the victim, were wounded while handling a grenade they found in a rural area outside Chaparral, a city in the west-central Colombian province of Tolima, police said.
The children, who ranged in age from 4 to 11, were playing with the grenade, which they found at a ranch in the Vega Chiquita area.
Investigators are trying to determine where the grenade came from, Tolima police chief Col. Wilson Mosquera told reporters.
The wounded children are being treated at San Juan Bautista Hospital in Chaparral and at a hospital in Ibague, the capital of Tolima.
The children involved in the incident are from poor peasant families, Chaparral Mayor Hugo Fernando Arce said.
Revolutionary Armed Forces of Colombia, or FARC, guerrillas operate in the area and the grenade may have belonged to them, officials said.
The weapon may have been used and failed to explode in one of the frequent firefights that occur in the area, officials said. EFE