GIORDANO'S store in the heart of Beijing's premier retail district remained closed yesterday, with four uniformed guards stationed at the main door. A metal shutter had been pulled down in front of the shop with a notice attached, proclaiming: ''Straightening out internal affairs, temporarily closed for business.'' The security guards, some armed with electric batons, refused to allow anyone into the store or say why it had been closed. The store received orders from an unknown authority to close at about 4 pm on Monday, the guards said. Staff inside the store, who were still working yesterday, also said they did not know why the shop had been closed, or when it might reopen. Neither of the store's managers was available for comment, staff said. The Wangfujiang store, which sells the full range of Giordano casual wear, has proved extremely popular with Beijing's increasingly fashion-conscious consumers since it opened last month, drawing in hundreds of shoppers every day.