Members of an alleged terrorist cell plotting to launch suicide attacks on Christmas shoppers and tourists in London were radicalised in jail, it has been claimed.
The alleged terrorist cell, based in Stoke-on-Trent, Cardiff and London is said to be linked to the banned extremist group al-Muhajiroun and its off-shoot Islam4UK.
Sources say the gang was planning a “spectacular” attack on commercial sites such as banks and shops along with “iconic” sites in London.
They were arrested after months of surveillance by MI5 as they prepared to launch their attacks in the week before Christmas, sources said.
The group of mainly British nationals of Bangladeshi origin, is said to have links with Anwar al-Awlaki, the radical al-Qaeda preacher based in Yemen.
It emerged yesterday that three men arrested were apparently radicalised while serving time in prison.
A neighbour in Cardiff said the three men were convicted of theft and drugs offences, and that they “went to prison as petty criminals and came out expressing extreme views.”
The man said he believed a “radical preacher” had “politicised” them during a stint in prison.
He said the men had grown long beards while in jail and later handed out leaflets at the Jalalia mosque encouraging people not to vote in this year’s general election, saying it was “unmuslim”.
Muslims leaders said they tipped off police about the group of extremists in the Welsh capital, where five men between the ages of 23 and 28 were arrested.
They said they had stopped the group from holding meetings in mosques in the last month and told them to “go elsewhere.”
Mosque officials informed police but it is thought that MI5 was already aware of the group.
The group, comprising about 15 to 20 young radicalised men, is understood to have held a meeting at a community centre in Cardiff less than two weeks ago, addressed by Abu Izzadeen, a radical preacher recently released from jail.
Counter-terrorism officers are understood to have been aware of the event at the Cathays Community Centre attended by up to 30 people.
Constantly adopting new titles, the group has held events under the banner Islam4uk and Islamic Pathways among others.
Saleem Kidwai, secretary general of the Muslim Council for Wales, said: “The Muslim community is aware that there is a small group of people who have links to extremists and they have been brought to the attention of police.
“This is no shock, the shock will be when the details are released of what they were planning to do.
“There was a group of 15 boys that the community was aware of, they were going to have a meeting and they were rejected by all the mosques.
“If you do not conduct your affairs within the rules of the club then you are not allowed in.”
In Stoke-on-Trent the arrests included men using the pseudonyms Abu Saif, 19, Abu Bosher, 26, and Abu Sumayyah, 25, a convert, who were arrested in another operation two years ago.
They had protested in favour of Islam4UK which was planning a march through Wootton Bassett against British troops in Afghanistan.
Lord Carlile, the terrorism watchdog, said the arrests marked a “significant” terrorist plot and charges were likely within days.
He said he observed part of the surveillance operation on the suspects which had been conducted for a long time.
The 12 suspects, aged between 17 and 28, were held during early morning raids by unarmed officers in London, Cardiff, Stoke and Birmingham on Monday.
Baroness Neville-Jones, the Security Minister, told the same committee that the threat to the UK’s security was “indefinite.”
Speaking before a meeting of the National Security Council, she said: “I would say it was an indefinite duration, yes, and of course this country also faces a threat from Irish terrorists as well.”
Al-Muhajiroun has been associated with members of the Operation Crevice fertiliser plot and a member of the group died in a suicide bombing in Israel.
Anjem Choudary, a former leader of al-Muhajiroun and Islam4UK, said: “I do a lot of activity and I have been to most of these towns. They say some of the people came to Islam4UK demos and it is possible but I don’t know for sure.
“People should be happy that they associated with us because we don’t believe they should attack this country, we just call for shariah [Islamic law]. Ours is a political and ideological struggle as opposed to a military one in this country.”