No group immediately claimed responsibility for the killings in the remote district of Tala Wa Barfak, but the government blamed ISIS terrorists who are making steady inroads into Afghanistan.
"Nine coalminers were martyred by unknown gunmen in Tala wa Barfak. They were heading home when their vehicle were stopped by gunmen," district governor Faiz Mohammad Amiri told AFP.
The governor of central Bamiyan province, apparently where the coalminers were from, confirmed the incident.
The rise of the ISIS terrorist group has raised the spectre of sectarian discord in Afghanistan, something that the country has largely been spared despite decades of war.
Until a few months ago ISIS terrorists were largely confined to the eastern province of Nangarhar bordering Pakistan, where it is notorious for brutality including beheadings.
But the government this week said the group was steadily expanding into other provinces.
Around 2,000 Shia Muslims in western Afghanistan staged a protest on Tuesday against growing sectarian attacks by the group and demanded protection from the government.
Last year Afghanistan witnessed a wave of attacks on Shias claimed by IS, which considers Shia Muslims apostates.
At least 14 Shias were martyred in October in a powerful blast at a mosque in the northern city of Mazar-e-Sharif, hours after gunmen targeted Shia worshippers in a shrine in Kabul and martyred 18 people