Commentary on Sections Powers Section 21: Stop and Question
60.This section provides a member of the armed forces on duty or a constable with the power to stop and question a person for so long as is necessary to establish their identity and movements.
61.Additionally, members of the armed forces may stop a person to question him or her about a recent explosion or incident endangering life, or about their knowledge of a person killed or injured in a recent explosion or incident. These additional grounds are intended to assist the military to undertake explosive ordnance disposal work, where they may wish to question people about explosions to gain knowledge which will help them ensure the safety of an area. Anyone who fails to stop or answer to the best of their knowledge and ability commits an offence.