- Police say that children are among the dead
- Official calls attack retaliation by the Taliban
- There has been no immediate claim of responsibility
Children were among the dead, all of whom were civilians, said Sayed Masoud Yaqoobi, a local police spokesman.
He warned the number of casualties could rise as several people have suffered life-threatening injuries.
The blast hit the market in Almar, a district of Faryab province near the border with Turkmenistan, around 11:30 a.m. local time Wednesday, Yaqoobi said.
There was no immediate claim of responsibility for the bombing.
Yaqoobi said police believe it was carried out by the Taliban, whom Afghan security forces have pushed back in the region.