Police in five European countries last month arrested more than 80 suspected Islamic militants in a combined operation allegedly prompted by fears of attacks during the World Cup in France.

The suspects, mainly Algerians, were arrested in France, Germany, Italy, Belgium and Switzerland. Police in the Netherlands and Britain - where a further eight Algerians were arrested a few days earlier under the Prevention of Terrorism Act - are understood to have been involved in the operation.

The arrests were a timely reminder of a little-noticed but increasingly important feature of EU co-operation. While politicians argue about the euro-currency, the profligate Common Agricultural Policy and the merits of a single market, EU police and intelligence agencies are well on their way to constructing what Brussels calls an area of "freedom, security, and justice", its euphemism for Fortress Europe.

It is being built by a Kafkaesque web of secretive, unaccountable committees, with titles such as K4, adopting programmes, with names such as Odysseus, Falcone and Eurodac, with new institutions like Europol, under the cover of ostensibly benign initiatives called "mutual assistance" or "joint action".

Policy decisions on asylum, immigration, stop-and-search powers, the installation of massive data bases, surveillance and telephone-tapping are frequently adopted as what EU ministers quaintly call "A points", decisions, made by officials, passed on the nod.

EU states recently agreed a barely-reported joint action against people participating "in a criminal organisation in the member-states of the European Union". Crimes are defined - extremely broadly - as offences carrying a sentence of four years or more.

The joint action catches anyone planning a crime "even where the offences concerned are not actually committed" and "even if that person does not take part in the actual execution of the activity".

EU justice and home affairs ministers also agreed to extend Eurodac, an EU computer data base for storing fingerprints of asylum applicants, to "illegal immigrants".

According to Statewatch, a London-based group which monitors civil liberties in Europe, they also agreed without debate the Falcone programme: training and co-operation between those involved in the fight against organised crime, including judges, public prosecutors, police, customs officers, and what the EU euphemistically calls "civil servants".

They agreed without debate to the EU Odysseus programme, designed to promote co-operation in the field of asylum, crossing of the EU's external borders and "combating illegal immigration".

Europol, the EU's policing organisation originally set up to combat drugs, has been extended to include "terrorism". EU ministers and officials can extend the list of "crimes" coming within Europol's grasp without telling national parliaments or the European Parliament.

Earlier this year EU ministers agreed, also without debate, to allow Europol to store information from sources outside the EU. Personal data stored by Europol can include "one or more characteristics of his/her physical, mental, economic, cultural or social identity".

Police and intelligence agencies in the EU, and elsewhere, have a crucial role combating increasingly resourceful groups of criminals and terrorists. But their task should not be carried out at the expense of unacceptable threats to civil liberties and at the price of an EU increasingly deficient in democracy.