http://www.telegraph.co.uk/news/uknews/terrorism-in-the-uk/8244622/Train-stations-on-alert-over-terror-threat-fears.htmlBritish Transport Police cancelled leave and called in extra officers after intelligence was received that terrorists could be planning attacks.
A security source said there was no ^imminent^ threat and the overall threat level had not changed but there was activity from one of a ^handful^ of extremist cells that cause concern at any time, leading to an adjustment in policing levels.
It is understood that ^intelligence chatter^ suggested that transport hubs in London could be a target.
It was unclear last night whether the terrorists were discussing suicide bomb attacks, or Mumbai-style shootings, or a combination of methods.
A Whitehall source said: "The assessment of the threat to transport hubs has been revised. The view is that there is a greater risk than before, so steps are being taken as a precaution."
There have been two serious terrorist plots in the last few weeks that have been linked to Britain.
On December 11 a suicide bomber blew himself up in Stockholm, Sweden while heading towards the central train station.
In Copenhagen, Denmark, last week, police arrested three men with a submachine gun, silencer and ammunition who were allegedly planning a Mumbai-style shooting spree.
Both plots had links to Britain ^ the Stockholm bomber, Taimour Abdulwahab al-Abdaly, had been living in Luton, while the alleged Danish terrorist cell had links to a network in Derby, the Daily Telegraph reported on Thursday.
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