An Afghan official says unidentified gunmen have killed at least seven coal miners in northern Afghanistan, revising the death toll which was earlier put at 13.

Faiz Mohammad Amiri, the district governor of Tala wa Barfak, in Baghlan Province, told RFE/RL's Radio Free Afghanistan that the miners were killed on January 6. He said three other miners were wounded in the attack.

Amiri said the miners were all members of the Shi'ite Hazara minority.

No group has claimed responsibility for the attack.

But Amiri said the attack was likely carried out by the Islamic State (IS) militant group, which has carried out a string of deadly attacks on Shi'ite Muslims in the country.

In July, the Sunni extremist group targeted Kabul's Shi'ite community in a suicide bombing that killed more than 80 people and wounded 130, the deadliest attack in the capital since the U.S.-led invasion in 2001.

IS militants were largely confined to the eastern province of Nangarhar, which borders Pakistan, one year ago, but the government says they have greatly expanded their presence since then.

