KIGALI, Dec. 17 (Xinhua) -- At least three children were killed by an explosive device in a village in northern Rwanda, a local official and police said Wednesday.

The incident took place on Tuesday in Cyumba Sector, Gicumbi District bordering Uganda at around 8:30 a.m. local time (0630 GMT).

Mayor of Gicumbi District Emmanuel Nzabonimpa told reporters that the children could have unintentionally picked unexploded ordnance while collecting firewood in a nearby forest.

The device could be an explosive remnant of war during the 1990s, the mayor added, noting that unexploded and abandoned ordinances were previously found by residents in the area and destroyed by security agencies. ■