A Causeway Bay shopping centre was sealed off yesterday, trapping hundreds of people as police searched for a gang of robbers. About 1,500 people were stuck in The In Square in Windsor House for up to three hours while about 110 armed police, many wearing bullet-proof vests, were deployed to seal off the 15-storey building and search it. The hunt came after three shots were fired during a robbery of the Chow Tai Fook jewellery shop in Paterson Street at about 1.55 pm. One suspect was found on the first floor of The In Square, but two were still on the run last night. The police operation closed Great George Street and nearby roads including the section of Gloucester Road next to Victoria Park until the start of the evening rush hour. The robbers sparked panic among lunchtime crowds as they ran into the shopping centre, followed two minutes later by police officers with guns drawn who sealed off the mall's three exits. Police said the robbers had planned their escape from the shop through the adjoining Yue Hwa Chinese Products department store to a back alley, across Great George Street and into The In Square. Two men, each with what is believed to be a Black Star pistol, entered the shop filled with three customers and 30 staff, said Superintendent Bill Cheung Man-piu. One of the robbers, all said to be in their 20s and dressed in suits, fired two warning shots into the ceiling before grabbing five Rolex watches and two gold necklaces worth $250,000. After less than a minute in the store, the men fled through security doors left open to attract customers. Another shot was fired as the robbers ran through Yue Hwa. They were joined by a man believed to have been the lookout before they disappeared. Student Grace Fong of the Chinese International School was chatting with friends in the first-floor Delifrance cafe when she saw men run by. 'I was grabbed by police and told to leave the place right away. I wasn't scared, I just didn't want to get hurt,' she said. Police toured the building with megaphones and checked occupants from the top floor down, releasing groups of people once they had been checked. A man matching a witness' description was found near a rear staircase on the first floor, but Superintendent Suen said the others appeared to have escaped. The building was reopened shortly after 5 pm.