Section 155(c) in Police Regulations, Bengal , 1943
(c)He is responsible that no greater volume of fire is used than the circumstances demand. He should normally order firing by specified individuals or by files: but he may order firing by sections, or volleys by not more than half the party at a time, if the attitude of the mob makes this imperative for the protection of his officers or for the protection of the life and property of others.
