A pensioner is believed to be in a very serious condition in Altnagelvin Hospital following a serious assault which took place in his Carndonagh home on Friday night.
The incident happened at about 9.30pm on Convent Road in the town. The 73-year-old man is understood to live alone. He was taken by ambulance to Altnagelvin Hospital in Derry.
A male aged in his 30s was arrested in connection with the incident.
The scene has been preserved for a technical examination.
Gardaí are appealing for information from the public. Anyone with information is asked to contact Buncrana Garda Station 074 - 9320540 or the Garda Confidential Line 1800 666 111.