Traffic is not being allowed into the city centre.
Last Updated: Saturday, 9 July, 2005, 22:47 GMT 23:47 UK
About 20,000 people have been evacuated from Birmingham city centre amid a security alert.
West Midlands Police asked people to leave Broad Street, the main entertainment hub and two other areas. Some city homes were also evacuated.
No vehicles are being allowed past the inner ring road into the city centre.
Police said a controlled explosion had been carried out earlier in the evening on a bus in Corporation Street, following a phone call from the public.
Officers now believe that the item destroyed had not posed a threat.
Police said the evacuation was a "proportionate response" to intelligence received, but were not giving specific details.
Birmingham resident Kenneth Kelsall told the BBC: "There is a lot of confusion, there appears to be no chance of anyone moving back into the city - but people are remaining quiet."
The BBC's Zoe Gough said there was confusion and people were trying to find out information but there was no panic.
'Gridlocked' streets
"Everybody is just being turned round and the main roads out of the city seem to be gridlocked, although traffic does seem to be moving," she said.
"I have seen some cars just pulled up and also people walking along with suitcases away from city centre as if they have been stranded there.
"People who have come here to have a good time have been trying to carry on with their evening, but the area being evacuated seems to be widening...
"The lot of roads are like ghost streets, when they normally would be packed with people. "
The assistant chief constable of West Midlands Police, Stuart Hyde, said he did not think the incident was connected to the bombs in London earlier this week.
"We are asking people who are there at the moment to go home, to have the evening off, this will help us considerably."
He said the decision to close such a large part of the city had not been taken lightly.
"We have made this decision after careful analysis and consideration and we are very, very grateful to the public for their understanding.
"We believe it is a proportionate response to the information.
"Finally I would ask members of the public to stay vigilant."
West Midlands Police announced they had received intelligence of a possible threat to the area at about 2015 BST.
Initially people were told to be on their guard, and that bars and restaurants were being searched. Motorists were also told not to come into the city centre.
However, about half an hour later, police said the city was to be evacuated.