HANOI, Vietnam (AP) — More Vietnamese families are coming forward with information their relatives may be among the 39 people found dead in the back of a container truck in southeastern England.

British police initially said they believed the victims were Chinese but acknowledged this was a "developing picture."

Police on Friday arrested three people on suspicion of manslaughter and conspiracy to traffic people. The 25-year-old driver of the truck remains in custody on suspicion of murder.

In Vietnam, the father of 20-year-old Nguyen Dình Luong feared his son was among the dead.

He told The Associated Press he had not been able to reach him since last week, when he told his father he would join a group in Paris that was trying to reach England.