Police in France and Belgium have arrested 26 new suspects as part of the investigation into the Essex lorry deaths.
Europol said a total of 26 arrests and 27 house searches were made across France and Belgium on Tuesday.
Vehicles, cash and electronic equipment were seized, and 21 migrants were taken to safety.
In coordinated raids on Tuesday, 11 Vietnamese suspects and two Moroccans were arrested in Belgium, where searches were carried out in Brussels and Leeuw-Saint-Pierre.
As part of the same operation, French police made 13 arrests in the Ile-de-France region, which includes Paris.
“The criminal organisation is suspected of facilitating the transit of mainly Vietnamese irregular migrants through Belgium and France towards the United Kingdom” a Europol spokesperson said.
“The suspects are believed to have hidden their victims before routing them towards their final destination across the English Channel.
“It is likely that the network has transported up to several dozen people every day for several months.
“These criminal activities were particularly dangerous due to the life-threatening conditions of transportation.”
Officials said the investigation was “prompted” by the Essex lorry deaths but covered wider people smuggling across Europe.
Ten teenagers were among the migrants found dead in a vehicle parked on the Waterglade industrial park in Grays in the early hours of 23 October.
An inquest, which has been adjourned until the end of criminal proceedings, found they died of suffocation and overheating.
One of the women who died had texted her parents saying she could not breathe as the container was being shipped towards Purfleet, writing: “I’m dying.”
Investigators found the container had been loaded on a freight ferry from the Belgian port of Zeebrugge, having previously travelled to Dunkirk and Lille in France.
Authorities in France, Belgium, the UK, Ireland and Vietnam are involved in the ongoing investigation.
Five people have so far been charged by British authorities, including the lorry driver who drove the container through Essex.
Maurice Robinson, 25, admitted 39 counts of manslaughter in April.
He also admitted one charge of acquiring criminal property, but denied a charge of transferring criminal property.
At the same hearing at London’s Old Bailey, co-defendant Gheorghe Nica, 43, denied 39 counts of manslaughter and conspiracy to assist unlawful immigration.
Romanian national Alexandru-Ovidiu Hanga, 27, of Hobart Road in Tilbury, denied conspiracy to assist unlawful immigration.
Christopher Kennedy, 23, of Corkley Road in Darkley, has previously denied the same offence.
Valentin Calota, 37, of Cossington Road in Birmingham, has not yet entered a plea to the charge of conspiring to assist unlawful immigration. The next hearing is due to take place on 28 September.
Two suspects arrested in connection with the case are challenging attempts to extradite them to the UK from Ireland.
Ronan Hughes, from Tyholland in County Monaghan, is accused of being a “ringleader and organiser” and faces 39 charges of manslaughter.
Eamonn Harrison, 22, of Mayobridge in County Down, faces the same charges.