The attack in the market was aimed at a police car but the police escaped unharmed, said Sonatullah Timor, the spokesman for the Takhar provincial government. The bomb, which was placed on a motorcycle, wounded 26 people, including children, he said.
It was not immediately clear who carried out the attack, but Taliban insurgents frequently target the country's security forces.
In a separate incident, a suicide bomber detonated his payload at a checkpoint in the eastern Nangarhar province, killing a local police commander and his bodyguard, according to police spokesman Hazrat Hussain Mashraqiwal.