A bomb in a market in western Afghanistan has killed four people.

A spokesman for the Herat provincial government said the explosion also wounded 12 people, including three policemen who were on patrol.

Muhiudin Noori says the bomb was planted next to a shop in the busy bazaar in Shindand district.

The blast was the latest attack targeting civilians in Afghanistan.

Earlier this week, 35 civilians died in multiple suicide bombings and a market bomb in two different cities in what was the deadliest day for civilians so far this year.