Two Irishmen have been charged with conspiracy to facilitate illegal immigration in the UK.
It comes after 10 people were found in a truck near Ghent in Belgium on Thursday.
The UK's National Crime Agency (NCA) said there were eight youths and two adults in the truck.
It said they are believed to be migrants for South-East Asia.
Four people were arrested in connection with the investigation.
On Thursday, Belgian authorities arrested the truck driver, a 64-year-old man from Glasgow while NCA officers arrested the two Irishmen in Dover.
A fourth man was arrested in County Antrim on Friday
The two Irishmen, arrested in Dover, were brought to Canterbury Magistrates court this morning and charged with conspiracy to facilitate illegal immigration.
They were remanded in custody.
Investigators have also carried out searches at properties in Northern Ireland and the UK.
They found two suspected firearms at an address in Kent.
The NCA regional head of investigation Gerry McLean said the international operation saved the migrants from a “very dangerous situation.”
“We have seen only recently in Essex the tragic consequences which these types of attempts can have,” he said.
“Working with partners at home and abroad, we are determined to do all we can to disrupt and dismantle criminal networks involved in illegal immigration, and our investigation into this matter continues.”
West Flanders Prosecutor Frank Demeester said the operation proves that international cooperation works in the fight against human trafficking.
