Four Vietnamese and a Tajikstan national sleeping in a Moscow sewing factory were killed in fire that broke out at Wednesday night (local time).
They were unable to escape because the factory owner had locked its doors from the outside, Le Minh Dan, an official with the Vietnamese embassy in Moscow, told Thanh Nien.
He said the fire was apparently caused by electrical problems.
The factory's owner was a foreigner, Dan said, without mentioning the nationality.
All the Vietnamese victims, including two women, did not have valid visas, the Vietnam News Agency reported, adding all of them have been identified.
Dan said the embassy has assigned people to meet with concerned local agencies to learn more about the accident.
Another factory fire in Moscow last month had killed five Vietnamese nationals in another accident suspected to have been caused by electrical problems.