THREE auxiliary police constables were slightly injured when their vehicle stopped suddenly near a taxi stand at the Shun Tak Centre, Sheung Wan, yesterday. Police said more than 20 auxiliary officers were travelling in two police trucks that left the Waterfront police station at about 1 pm for target practice. As the first truck was turning into the centre, the driver braked suddenly to avoid a taxi that had stopped. Three of the auxiliary policemen sustained minor injuries. They were taken to Queen Mary Hospital where they were treated and discharged.