The authorities are attempting to establish if four men who turned up for treatment at a Co Louth hospital last night are linked to an earlier incident in Co Armagh.
The men, aged between 24 and 34, presented themselves at the Louth Hospital in Dundalk with burn injuries at 10pm.
An hour earlier, a gang set alight a 21-year-old woman and her 33-year-old boyfriend in a remote area 11km from Armagh.
The victims were named locally as Lisa McClatchey and Thomas O’Hare.
They also set fire to the couple's house.
The woman is currently in a critical condition and her partner has serious injuries.
RTÉ News understands that the four brothers, currently receiving treatment at St James’s Hospital special burns unit, are originally from the Market Hill area of Co Armagh.
Two have addresses in Northern Ireland and the other two have been living in the Dublin area, one in Balbriggan and the other in Crumlin.
According to reliable sources, none of the brothers has any known links with a paramilitary organisation.
All four are being described as in a 'critical condition'.
