POLICE yesterday searched a Yau Ma Tei building, housing a trading company, which had been raided by three men armed with a rifle and grenade. Wai Ching Street between Jordan Road and Saigon Street was cordoned off while officers searched the 18-storey Wai Ching Court just after 3 pm. No arrests were made. Detective Chief Inspector Cheung Yim-fui, said more officers were deployed to the scene because they were twice told by the victim that the gang was armed. Police said the trio entered the Alex Trading Company, tied and blind-folded the owner, before escaping with $500 in cash. A man armed with what appeared to be a shotgun robbed a Tuen Mun petrol station of $3,000 in cash and 24 cans of Coke early yesterday. In another robbery, two men raided a Ngau Tau Kok company and fled with about $150,000 worth of computer parts.