The home of two brothers critically injured in a fire was raided by police investigating a shocking attack in which a young couple were doused in petrol and set alight.
Lisa McClatchey, 21, and Thomas O'Hare, 33, are battling for life in hospital in Northern Ireland after being burned in the attack which destroyed their Co Armagh home.
Police have turned their attention to four men, believed to be brothers, who also presented themselves with burns at a hospital over the border in Dundalk about an hour after the couple were targeted.
The Police Service of Northern Ireland (PSNI) also confirmed a house was searched on Tuesday on the northern side of the border following the savage attack. A spokeswoman said: "Police searched a house in Clady, Co Armagh, (on Tuesday) as part of their investigation into the attempted murders."
Sources close to the inquiry confirmed police believe at least two other people know exactly what happened when the gang went into Ms McClatchey and Mr O'Hare's isolated home.
Detectives in the Irish Republic are waiting to question the four men, who are critically ill and who have since been transferred to St James's Hospital in Dublin. They are not under armed guard.
It is understood the men, aged between 24 and 34, are from the south Armagh area. Police on both sides of the border are trying to establish if they are linked to the attempted murders.
A number of items were removed for further examination after Tuesday's searches at the premises in Clady, near Markethill.
The attack on the couple drew widespread criticism, with the local Sinn Fein MP Conor Murphy, nationalist SDLP and Ulster Unionists all expressing revulsion.
Democratic Unionist leader the Rev Ian Paisley added his voice, challenging Sinn Fein to urge people with information to pass it on to the police. The North Antrim MP claimed the Armagh inquiry was a "litmus test" for the party's attitude towards law and order.
