Three of the five men killed in an explosion at an industrial unit were originally from Lithuania, police have confirmed.
Lincolnshire Police said officers are still working to establish the identity of the other men who died and a sixth victim who was critically injured in the blast in Boston on Wednesday night.
A spokeswoman said: "We can confirm that three of the fatal casualties are believed to be Lithuanian nationals and are aged 24, 26 and 32. Arrangements are being made to contact all next of kin and family members so that formal identification procedures can take place."
She added that inquiries were also being carried out to identity the other fatalities and the man being treated for severe burns at Birmingham's Queen Elizabeth Hospital.
Meanwhile, a police cordon placed around the unit has been extended to include other parts of Boston's Broadfield Lane Industrial Estate and further business units are currently being examined as part of the ongoing investigation.
Investigators revealed on Thursday that they had discovered evidence which suggested the unit was being used as an illegal distillery when the explosion took place.
Superintendent Keith Owen, of Lincolnshire Police, said: "What I can confirm is that we have found chemicals on the premises which tend to indicate either the manufacture or production of alcohol."