Update 9.30pm: A man arrested in connection with a serious assault in Meath has been released without charge.
Gardaí said a file will now be prepared for the Director of Public Prosecutions.
Gardaí in Meath have arrested a 22-year-old man in connection with a serious assault that occurred in Navan yesterday.
Gardaí said the man is being detained in Navan Garda Station under Section Four of the Criminal Justice Act 1984.
A young man remains in a critical condition today after the attack on Watergate Street.
Gardaí stated that the injured party remains in Beaumont Hospital.
Gardaí say they are following a definite line of inquiry following a serious assault in Co Meath yesterday.
A young man remains in a critical condition in hospital this morning after the attack on Watergate Street in Navan at around 3am.
He was taken by ambulance to Our Lady of Lourdes Hospital, Drogheda and was then transferred to Beaumont Hospital, Dublin.
Gardaí are continuing to appeal for anyone who was in the Watergate Street area between 2.45am and 3.30am on Saturday and who may have witnessed the assault to come forward.
They are also looking to speak with any motorists who may have passed through Watergate Street around those times and have dashcam footage.
People with information are asked to contact Navan Garda Station on 046 - 9036100, The Garda Confidential Line 18000 666 111 or any Garda Station.