A man has been arrested after an armed siege at a pub in County Cavan prompted by the fatal shooting of a 56-year-old woman on the Irish border.

The Garda Síochána had imposed a media blackout on the incident, which took place in Bailieborough overnight. It confirmed that a 56-year-old man was arrested, in relation to the woman's death, after a nine-hour stand-off with gardaí at Nixy's The Square Bar in Baileborough, which ended – without injuries – at about 3am.

The siege began after Patricia Kierans' body was found in a house on the outskirts of Bailieborough on Thursday evening. The mother-of-four had earlier said goodbye to her youngest child, who was emigrating to Australia to join his three siblings.

It is understood the four adult children – Oliver, Gerard, Julie and Shane – were alerted after their mother's sister became concerned when repeated phone calls were not answered. Officers called at her house and found her body inside.

An examination established she had received a shotgun blast to the body.

Kierans had been spotted in the area on Thursday morning. Gardaí think she was murdered in the afternoon.

While at the scene they received a call about an incident at the nearby Nixy's bar and restaurant. Staff said they had been ordered out of the pub by a gunman who warned them to stay away. There were no customers there at the time.

A trained negotiator, attached to the Special Branch in Dublin, was called in along with officers from the two special units. The suspect reportedly lives and runs a business in the town.