Tran Thi Hue (C), grandmother of 30-year-ola Le Van Ha, who is feared to be among the 39 people found dead in a truck in Britain, is consoled by relatives inside their house in Vietnam’s Nghe An province (Photo: AFP/Nhac Nguyen)

The 31 men and eight women found dead were initially identified as Chinese, but several Vietnamese families have come forward saying they believe their relatives are among the dead.

The grim case has cast light on the extreme dangers facing illegal migrants seeking better lives in Europe.

Many of the suspected victims came from impoverished villages in central Vietnam, a feeder of illegal migrants chasing promises of riches overseas.

Few were believed to be carrying identification, and families in the area have anxiously awaited news of their loved ones.

A security source in Vietnam said a team had been dispatched to the area on Sunday to collect DNA samples from relatives of suspected victims.

"We have started collecting hair and blood samples of families," the source told AFP, speaking on condition of anonymity.

The father of one of the missing men, Nguyen Dinh Luong, confirmed to AFP that samples were collected earlier Sunday.

"Police said the results would take time, they didn't say when they would be available," Nguyen Dinh Gia told AFP from central Ha Tinh province.

Vietnam's Ministry of Public Security has tasked various agencies to probe whether the migrants were smuggled overseas illegally, media reported.

The security source said four people had been taken into custody for allegedly organising illegal trips abroad, but they have not been formally charged.

Waiting game

The Northern Irish driver of the refrigerated trailer discovered in an industrial park on Wednesday in Essex, southeast England, has been charged with manslaughter and people trafficking.

Another Northern Irishman was also arrested in Dublin on Saturday, while three others held over the deaths in Britain have been released on bail, police said Sunday.

As the investigation played out, worshippers gathered in Phu Xuan village in Nghe An province to pray for the missing, kneeling before a priest who delivered a solemn sermon.

"We gather here to pray for all the 39 victims," Father Nguyen Duc Vinh said before a packed cathedral.

"We don't know yet whether they were our children," he added as the congregation sang hymns.

Parents in the area have set up makeshift altars for their missing loved ones, many whom have not been heard from since the truck was discovered.

The mother of missing 28-year-old man Vo Ngoc Nam said she last heard from her son days before the container was found.

He messaged to say he was going to Britain from Romania, where he had been working for several months.

"I have been waiting anxiously over the past few days for any news from him, but we got nothing," the stricken mother told AFP.

Most of the country's illegal migrants come from a handful of rural provinces in central Vietnam, where there are few jobs on offer and incomes sag well below the national average.

Vietnamese migrants often embark on dangerous overland routes through eastern Europe en route to the UK, paying smugglers tens of thousands of dollars for the trips.

They can pay up to US$40,000 for the journeys, greased by traffickers along the way who prey on vulnerable migrants.

Many end up working in Britain illegally, often in nail bars or on cannabis farms, heavily indebted and subject to exploitation.

VNF ( AFP )