The mine went off as a group of young boys and girls were playing with it in the Geru district of Ghazni province on Sunday, said the provincial head of the information and culture department, Hamidullah Nisar.
"An unexploded mine left over from the time of the Russian invasion went off when they were playing with it," Nisar told AFP.
"Unfortunately, it killed nine children."Ghazni police said the children -- five girls and four boys -- were aged from four to ten years old.
Swathes of Afghanistan are littered with unexploded mines, grenades and mortars from decades of conflict, spanning from the Soviet invasion in 1979, the civil war that followed, and the 20-year Taliban insurgency against foreign-backed governments.
Violence has reduced dramatically since the Taliban seized power in August 2021, ending their insurgency.
Unexploded ordnance and mines, however, still claim lives regularly, with the International Committee of the Red Cross saying children are the main victims.
Also on Sunday, another child died and five other people were wounded when unexploded ordnance went off in Herat province, local police said on social media platform X, formerly Twitter.
