Three labourers were killed and six critically injured after an explosion took place at a stone quarry in Odisha's Rayagada district on Friday.

The blast which rocked the quarry occurred when the labourers were loading stone chips on a tractor, instantly killing three of them.

According to police, six other workers were seriously injured after being hit by boulders and stone pieces following the blast. The deceased include two women as well.

The injured labourers were rushed to Gunupur hospital soon after.

An investigation is underway to ascertain the cause of the blast.