A man has been arrested in connection with the aggravated burglary at the home of a 96-year-old woman in Buncrana, Co Donegal at the weekend.
The 48-year-old man is being detained at Buncrana Garda Station.
Margaret 'Greta' Lilly was punched in the ribs and had money stolen from her during the burglary at her home in Aghilly.
She spent four days in Letterkenny General Hospital.
Inspector David Murphy described the incident as a "despicable act".
Gardaí are continuing to appeal for information in relation to the aggravated burglary and are asking people to contact them at Buncrana Garda Station on 074-9320540.
A Buncrana businessman has offered a reward of €5,000 for information leading to a prosecution in the case.
George McLaughlin said he has known Ms Lilly for many years and was so annoyed by the attack on her that he decided to put up the reward.
Elsewhere, an elderly brother and sister who were robbed yesterday at their home outside Kinsale in Co Cork are said to be very shocked but uninjured following the incident.
The 79-year-old man and his 76-year-old sister were set upon as they arrived home to their isolated cottage in Dunderrow shortly after 2.30pm.
Three men, who were inside the cottage, came out demanding money from the pair and took off after grabbing the elderly man's jacket and the woman's handbag from the front seat of their car.
It is understood the three men escaped with a small sum of money.
Gardaí in Bandon have appealed for any witnesses who might have seen the three men in a silver/or white car in the area between 2pm and 4pm to contact them.
The siblings were discovered in a distressed state by a relative who had called to visit them.