They have summoned individuals for questioning, said Senior Colonel Nguyen Tien Nam, deputy chief police officer of the central province.

They will not only be looking into reports by the 10 families who've reported children missing since Friday last week, but also other similar incidents that have happened over the last five years.

This is the first time that the province has decided to investigate a human trafficking ring believed to smuggle locals into Europe as a criminal activity.

Last Sunday, the Ministry of Public Security sent a team to Ha Tinh to assist the local police in collecting DNA samples of the parents with missing children, which would be sent to the U.K. to help determine whether they are among the 39 people found dead inside a refrigerated container in Essex on October 23.

"Most [of the families] have cooperated, some have their own difficulties so haven't been able to provide full information. Currently I believe we'll have to wait for the U.K. authorities' announcement before we can confirm whether there are Vietnamese among the 39 bodies," Nam said.

The 10 families who have reported children missing come from Can Loc District's Thien Loc, Vinh Loc Communes, Nghen Town, Dau Lieu Ward in Hong Linh Town and Cuong Gian Ward in Nghi Xuan District.

In the neighboring Nghe An Province, 18 other families have also reported their children missing in Europe around the same time of the U.K. truck disaster.

On October 23, U.K. emergency services discovered the bodies of 38 adults and one teenager, suspected immigrants, in a refrigerated container truck at Waterglade Industrial Park in Grays, Essex County, east of London.

Police initially believed all of the dead were Chinese nationals, but later said "this is now a developing picture" amid reports several may be Vietnamese.

Maurice Robinson, the 25-year-old truck driver, of Craigavon in Northern Ireland, has been charged with 39 counts of manslaughter and other offences including conspiracy to traffic people.

Three other people arrested in connection with the investigation have been released on bail until November 11-13.

Vietnam reported 490 human trafficking victims last year, according to the U.S.'s 2019 Trafficking in Persons Report.

Some 70 percent of Vietnamese trafficking cases in the U.K. between 2009 and 2016 were linked to labor exploitation, with young people forced to work in cannabis production and nail salons, according to a British government report released in 2018.