A Birmingham station was evacuated and part of the city centre sealed off last night after two suitcases were discovered abandoned on a platform.

Just hours after plain-clothed police officers shot dead a suspected suicide bomber at a London tube station, officers in Birmingham closed Snow Hill station and arrested a man under the Prevention of Terrorism Act just after 5.30pm.

***

Were you caught up in the drama at Snow Hill? Click here to send us an email

***

Hundreds of commuters were left stranded and forced to find alternative routes home after parts of Colmore Circus and Colmore Row were also sealed off.

A spokesman for British Transport Police said the security alert was triggered when an off-duty officer from West Midlands Police thought he saw one of four men whose images had been released earlier in the day by the Metropolitan Police.

Police believe the four men captured on CCTV cameras were responsible for planting a series of bombs on three underground trains and a bus that failed to detonate on Thursday.

Army Bomb Disposal Unit experts were called in to examine the two suitcases at Snow Hill but no explosives or bombs were found in the luggage and Snow Hill station was reopened just before 8.30pm. The man, who is believed to have been travelling on a train arriving at Snow Hill, was released last night without charge.

One station worker, who asked not to be named, said: ?It was very organised. We are trained for it.

?Even though it was the evening rush hour and there were thousands of people, everyone was fine.?

This is the second security alert to hit Birmingham. More than 20,000 people were evacuated from Broad Street and The Arcadian on July 9.

Last night Sergeant Roger Jones, of British Transport Police, said: ?The call was made in good faith following the release of CCTV images by the Met in connection with the four men they are seeking.?

Ged Burgess, of Central Trains, said: ?We had trains running from Moor Street to Solihull and to The Hawthorns. People using the Metro were able to go up to St Paul?s station to get trams to The Hawthorns. New Street was also open and buses were running along diverted routes, so it wasn?t a transport shutdown like in London after the July 7 bombings.?

This latest bomb scare came hours after plain clothes policemen shot an Asian man as he tried to board a train at Stockwell Tube station, in south London. Officers believed the man was an accomplice of the four bombers who targeted three Tube stations and a bus on Thursday.

According to witnesses, the man was shot five times at close range by an officer with an automatic pistol.

Witness Mark Whitby said a young Asian man was shot five times after he jumped on a train. He said the drama began as the tube train was stationary with its doors open at Stockwell station. He then heard people shouting: ?Get down, get down!?

?An Asian guy ran on to the train. As he ran, he was hotly pursued by three plain-clothes police officers,? he said. The man tripped and was pushed to the floor, then one of the officers shot him five times.

?One of the police officers was holding a black automatic pistol in his left hand. They held it down to him and unloaded five shots into him. I saw it. He?s dead, five shots, he?s dead,? added Mr Whitby.

Metropolitan Police Commissioner Sir Ian Blair said the shooting was ?directly linked? to anti-terror operations. He said officers opened fire after the man was challenged and refused to obey.