Two men have been arrested in Derry in connection with the investigation into the serious assault of a man in his 20s in Lifford, Co Donegal.
The PSNI, which is assisting gardaí in the investigation, arrested the men on suspicion of serious assault.
A man in his 20s is in a critical condition at the Royal Victoria Hospital in Belfast, after he was attacked in his home on Monday morning.
It is understood a number of masked individuals entered the house armed with iron bars.
The man's father, who is in his 60s and who was in the house at the time, was also assaulted.
He was treated at Letterkenny University Hospital for non-life threatening injuries.
Gardaí have carried out door-to-door inquiries in the Lifford area and are working to identify the suspects and the vehicle in which they travelled.
They have appealed for any witnesses, particularly anyone who may have camera footage (including dash-cam) from Coneyburrow Road, Lifford, between 10am and 11am on Monday 20 January, to contact Letterkenny Garda Station on 074 9167100, the Garda Confidential Line on 1800 666 111, or any garda station.
Sinn Féin Councillor Dakota Nic Mheanman said the community is deeply worried and taken aback by what has happened.
Additional reporting Shane Ó Curraighín
