Missing boy, 9, blue hoodie, East Anglia

I lost my younger brother, 9-year-old Omar Hassan, yesterday around 3pm. He was wearing a bright blue hoodie with a small red dragon patch on the sleeve and a black cap with a white logo. We last saw him near the Market Place in Norwich, East Anglia, before he wandered off toward St. Andrew's Street. He has short, curly brown hair and wears round glasses that slide down his nose when he's excited. I'm really worried—he's shy but very clever, and this is completely out of character. If anyone spots him or knows where he might be, please contact me right away; anything helps.