Passengers were evacuated from trains arriving and departing King's Cross, St Pancras, Charing Cross, Victoria and London Bridge.
On the London Underground, only Central Line services were unaffected as all other lines were shut down for more than three hours. Services were gradually resumed late last night.
The call was made at 6.20pm, causing severe disruption for tens of thousands of commuters.
Traffic came to a standstill outside Victoria station as people queued for buses. Among them was Collette Pickard, 27, a travel agent from Bromley, south-east London, who said: 'It's absolutely pathetic, I'm now going to be hours late home from work. The police are like headless chickens. As soon as there is the slightest problem the whole of London closes down.'
Dennis Scott, 31, on his way to Balham, said: 'Just one phone call brings British Rail to its knees. I sometimes wonder if we really are winning the battle against terrorism.'
Janet Marshall, 29, a secretary from Sidcup, Kent, said: 'I'm absolutely sick and tired of this happening every other week.'Reuse content