The insurgents abducted the civilians on Tuesday afternoon in the district of Sholgara and later killed them, according to Sayed Arif Iqbali, the local police chief.
There was no immediate confirmation from the Taliban that they were behind the attack in Balkh.
The violence comes as the Taliban have said their peace deal with the United States, signed at the end of February in Qatar, was nearing a breaking point, blaming Washington for alleged violations of the deal that the U.S. denies.
In the southern Kandahar province, three children were killed and five were seriously wounded when a mortar shell hit in the district of Daman, according to Bahir Ahmadi, the spokesman for the provincial governor.
The Taliban blamed U.S. forces for the attack, and a Taliban spokesman, Qari Yusouf Ahmadi, claimed the children were killed in a drone attack. However, U.S. military spokesman Col. Sonny Leggett denied any use of weapons in the area.
Ahmadi, the governor's spokesman, said an investigation was launched into the mortar attack on Tuesday evening.
"We reiterate our calls for the Taliban to reduce the violence," Leggett tweeted.
The attacks come as Afghanistan braces for the new coronavirus, which has killed at least 14 people from among 423 confirmed cases.