SEVEN officers were injured when police mounted a pre-dawn raid on the Tsuen Wan hideout of an armed gang, the High Court heard yesterday. Shots were fired and two hand grenades were thrown during the operation, which led to the discovery of a cache of firearms, including five pistols and 176 rounds of ammunition, the court was told. Appearing before Mr Justice Ryan were Leung Sui-chiu, 25, and Ng Kam-fook, 24. They had pleaded guilty to three joint charges of possession of arms and ammunition without a licence, use of arms and ammunition with intent to resist arrest and false imprisonment. Ng confessed to discharging a firearm with reckless disregard for the safety of others. Leung admitted possessing arms and ammunition with intent to endanger life, and using ammunition with intent to resist arrest. Leung also pleaded guilty to two charges of robbery and two of possession of a firearm while committing a hold-up. The two men will be sentenced by Mr Justice Ryan at a later date. Senior Crown Counsel Paul Madigan told the court that at about 4.50 am on December 2, 1992, police used loud-hailers and also telephoned a 23rd floor flat at Kwong Chau House, Tsuen Wan Centre, telling the occupants to surrender. The six occupants, including Leung and Ng, fired bullets through the door from inside the flat. Leung later told police that in order to stop the officers, at least one grenade was thrown and exploded inside the premises. He said he then handed a plastic bag with three hand grenades to two other men, who had climbed out of the flat window. However, Leung said they failed to grab the bag and it fell on to the street and a grenade exploded. However, this was disputed by the Crown which maintained that a videotape showed a man resembling Leung throwing a grenade out of the window. The explosion injured seven officers below who were forming part of a cordon. One was blinded in one eye. Leung, Ng and another man escaped from the flat through the window and climbed drainpipes to a 27th-floor flat. They threatened a man and two women inside with a pistol and a rifle, and detained them in the premises against their will. They were arrested and three pistols, one rifle and 44 rounds of ammunition were seized. The 23rd-floor flat which had been occupied by Leung, Ng and the others was also searched and six hand grenades, a fly-off lever and two safety rings of grenades, 16 ammunition shells, fragments from a grenade and 118 rounds of ammunition were found. Police also recovered another pistol which was in pieces and another eight bullets from the podium of the building. Under caution, Leung also admitted taking part in two restaurant robberies which occurred in Mongkok and Shau Kei Wan on October 20 and 30, 1992. In each hold-up, pistols were used and Leung was among the gang who escaped with about $43,000 in cash and other valuables. During the Shau Kei Wan robbery, shots were fired into the ceiling.