Thousands of people evacuated from Birmingham's city center faced "a real and very credible threat," police Chief Constable Paul Scott said Sunday. Scott declined to describe the nature of the threat, but said intelligence indicated it was genuine. Some 20,000 people were evacuated Saturday night because of intelligence suggesting a security threat. It was unclear whether the threat had any ties to Thursday's deadly terrorist attacks in London. Stuart Hyde, assistant chief constable of the West Midlands police, said Saturday night that there was no evidence linking the two. The evacuation of the bustling Broad Street entertainment district and the city's Chinese quarter followed intelligence warning of a "substantial threat," Hyde was quoted as saying by The Associated Press.