Metropolitan Police Chief Wiroj Chantharangsi has warned Thai fans to mind their manners and not to link politics to the Asean Championship match against Singapore in Bangkok on Sunday. He said Thai fans should remain concerned about the country's reputation and exhibit good sportsmanship. Metropolitan police plan to step up security at the stadium, with both uniform and plainclothes officers deployed inside the sports facility. In their first meeting earlier in the week, a controversial penalty led the Thai team to walk off the field in protest before returning 15 minutes later.The Nation