At least six Pakistani civilians were killed while 17 others sustained injuries after Afghan Border Forces opened fire in Balochistan’s Chaman district, officials said on Monday.

The Pakistan army said Afghan border forces had opened "unprovoked and indiscriminate fire of heavy weapons including artillery/mortar onto the civilian population" at the Chaman border crossing.

The Pakistani troops retaliated, the army statement said, without giving details of any losses on the other side.

Meanwhile, the injured persons have been shifted to a local hospital, and the police have cordoned off the area.

Afghan security sources said the clash started after Pakistani forces demanded Afghan forces stop building a new checkpost on their side of the border.