Thousands of police have carried out a co-ordinated series of raids against suspected Islamic militants in a number of European countries.
The main focus of the operation was in France, where police say they have arrested more thanfifty people they suspect of being linked to the militant Algerian group, the GIA.
Raids also took place in Belgium, Germany and Italy, while anti-terrorist police in Britain and Switzerland were also consulted.
The operation comes two weeks before the football World Cup in France; correspondents say security is particularly tight to prevent any group from using the occasion to carry out attacks.
From the newsroom of the BBC World Service