Anti-terror police search homes after dawn raids ahead of 'Christmas attack'

Anti-terror police were scouring homes in four cities today as officers began questioning 12 men over fears of a Christmas attack on British cities.

Shoppers, travellers and party-goers are believed to have been possible targets of a suspected al Qaeda-inspired plot for a "mass-casualty" atrocity.

Searches of properties in east London, Cardiff, Stoke and Birmingham are expected to take several days to complete but sources say no bomb-making materials or weapons have been found so far.

The 12 suspects, aged between 17 and 28 with at least five of Bangladeshi origin, were held during early-morning raids by unarmed officers yesterday.

In London three men, one aged 17, were arrested at separate homes in Newham and Tower Hamlets while a fourth house was also being searched.

The men are said to have plotted to attack shopping centres and landmark sites such as Whitehall and London's Eurostar terminal.