The interior ministers are also considering creating a flying squad of counter-terrorism experts and giving Muslim clerics European Union training, as well as introducing positive profiling of air passengers based on biometrics rather than ethnic background. The proposals were unveiled as John Reid, the Home Secretary, said that the police appeared to believe that there was material of a “substantial nature” emerging from their inquiries into the alleged plot to blow up airliners bound for the US.

As Mr Reid and some of his fellow interior ministers met in the Home Office, the Metropolitan Police went to the City of Westminster Magistrates’ Court to seek extra time to question the 23 terrorism suspects arrested last week in raids in London, Birmingham and High Wycombe, Buckinghamshire.

At closed hearings, a senior police officer presented the case for extra time to a district judge. The suspects, who are being held at two London police stations, were informed of the court’s decision via videolink. Just after 10pm Scotland Yard said that it had been granted permission to detain two of the suspects until Monday and 21 until Wednesday. One person who had been arrested in the Thames Valley area was released without charge.

Police can detain suspects for up to 28 days with court approval before pressing charges or releasing them.

Mr Reid said after the meeting that the terrorist threat was Europe-wide and needed to be tackled on an international level. The interior ministers were briefed by Dame Eliza Manningham-Buller, the MI5 Director-General, and Assistant Commissioner Andy Hayman, the head of special operations at Scotland Yard.

Mr Reid said: “What is clear to all of us is that we face a persistent and very real threat across Europe. It is a threat we face here in Britain as individuals and as communities, but it is not unique to the UK. It affects us all across the European Union.”

The meeting was attended by ministers from Finland, France, Germany, Portugal and Slovenia; Franco Frattini, the European Commission Vice-President; and Gijs De Vries, its counter-terrorism co-ordinator. Many of the measures discussed are already part of the EU action plan put forward during the British EU presidency.

Signor Frattini said that the internet should be made a “hostile environment” for terrorists. “I think it’s very important to explore further possibilities of blocking websites that incite to commit terrorist actions,” he said, adding that he would propose EU training for imams as part of a drive to prevent the radicalisation of Muslims. There have been complaints by Muslim leaders in Britain that some imams speak Urdu, which is not understood by many younger Muslims born and raised in Britain.

Other proposals include a greater sharing of information between EU police forces; more research on explosives, particularly liquid-based ones; and further attempts to improve the traceability of commercial detonators and explosives. The ministers pledged £237,000 for urgent research into detecting liquid explosives, as well as the continued development of a Europol database on weapons and explosives.

The police continued to search 22 of the 46 targeted residential and business premises in London, the West Midlands and Thames Valley. The most high-profile search is at King’s Wood in High Wycombe, where specialist officers are combing woodland for traces of explosives. A resident of Hawthorne Road, High Wycombe, where the latest suspect was arrested, said: “His parents are just devastated. They don’t believe it and neither do we. It’s a real shock. They are just very nice people, very good guys.”

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