Public prosecutors and police authorities took action against people-smuggling gangs across Europe on Tuesday.
In addition to operations in France, Belgium, the Netherlands and Britain, there were police actions in several German federal states, according to prosecutors in the north-western city of Osnabrück, who were in charge of the German side of the operation.
Results and background are to be presented this Wednesday at a Eurojust press conference in The Hague.
Eurojust, the European Union's agency for judicial cooperation in criminal matters, and Europol jointly coordinated the operation.
In Germany alone, 900 officers from the Federal Police and the Osnabrück Police Headquarters were involved in 36 searches of properties, with 18 people arrested in Lower Saxony, Bremen, North Rhine-Westphalia and Baden-Württemberg.
They are suspected of having been involved in a human-trafficking gang and of the commercial smuggling of foreigners.
People-smuggling is a high-profile issue in the English Channel, which many refugees try to cross in rubber dinghies in order to get to Britain.
The French Interior Ministry says 777 attempts to cross the Channel in small boats were registered between the beginning of the year and June 13.
These involved a total of 20,132 people, an increase of 68% compared to the same period last year, which saw record numbers of attempted crossings.
Officers arrested six men and a woman in the Docklands and Catford areas of London on Tuesday, the National Crime Agency (NCA) told Britain's Press Association (PA).
PA said it "is believed to be the 'biggest ever' international operation targeting criminal gangs suspected of people-smuggling across the English Channel."
