Vietnam police have arrested two people for trafficking in connection with the death of 39 migrants whose bodies were found in a truck in Britain, many of them feared to be Vietnamese.
The move comes after British police arrested four people over the tragedy and are now seeking to question two brothers from Northern Ireland who have links to the road-haulage and shipping business.
The victims were initially identified by British police as Chinese, but many are now believed to be Vietnamese after families in central Vietnam said their loved ones had not been heard from.
Vietnam said Friday two people were arrested for alleged involvement in the case, which has exposed the dangers of illegal people-smuggling from the Asian country to Europe.
Many of the suspected victims came from central Ha Tinh province, where the two arrests were made in connection with "the case of 39 dead bodies found in a container truck in the UK", according to a statement on the local police website.
The pair were accused of "organising and brokering for other people to go abroad and stay abroad illegally", it said.
The bodies of the victims were found in a refrigerated trailer on October 23 in an industrial park in Essex, east of London. Police said the truck came from a Belgian port.
The 25-year-old driver of the truck, Maurice Robinson from Northern Ireland, has been charged with 39 counts of manslaughter.
He was also charged with conspiracy to traffic people, conspiracy to assist unlawful immigration, and money-laundering.
Prosecutors said he was involved in an international trafficking ring as he appeared in court this week.
Three others who were arrested have been released on bail.
Several Vietnamese families said they heard from relatives before their crossing into the UK but have had no contact since.
Vietnam has said Britain sent documents to help with the complicated task of identifying the bodies, many of whom were believed to be carrying falsified passports.
DNA samples have also been taken from relatives in Vietnam to help with the process.
But so far none of the dead have been officially identified.
The truck tragedy has plunged communities in central Vietnam into mourning, as families desperately wait for news.
The region has long been a source of illegal migration to Britain for people seeking better lives.
Migrants often work in nail bars or cannabis farms, heavily indebted and vulnerable to exploitation.