MAZAR-I-SHARIF, Afghanistan, Dec. 28 (Xinhua) -- Six Afghan children dead in an explosion in the country's northern province of Balkh, a local official said Thursday.

"A group of children were playing near a school in Dawlat Abad district Wednesday evening, but one of the kids stumbled on a piece of stray ordnance, causing a blast which left the innocent children killed," district Administrative Chief Karim Bay told Xinhua.

The victims ranged from six to 12 in age, the source added.

Landmines and anti-personnel mines kill or maim more than 50 people every month in the militancy-hit country, according to officials.

Unexploded ordnance and explosive remnants of war also frequently cause casualties among the Afghans elsewhere in the country.