The woman, who has been named locally as Peggy McGarvey, died at her home in the Linseys Hill area of Armagh at 7.40am on Tuesday.

She was the mother of Oscar-nominated cinematographer Seamus McGarvey.

The Fire Service was called when care workers, who were coming to the house, raised the alarm.

One of the Mrs McGarvey's neighbours tried to save her from the fire.

"I opened the front door and it was just covered in black smoke. I tried to go in for a bit but the smoke just made you fight back, so I came running back out."

Police and paramedics arrived at the scene and went into the house, but quickly came back out.

"The paramedic said there was nothing they could do, there was too much smoke and she was already gone at that stage," he added.

The fire is believed to have started accidentally but an investigation is being carried out.

Last Tuesday, 78-year-old Sadie Ferguson died in a house fire in Dromara, Co Down.

Meanwhile, in Co Antrim, 64-year-old Albert Kane died after his home caught fire at Bush Road, near Dervock later that night.

His neighbour's adjoining house was also destroyed when the fire later reignited.

Health Minister Edwin Poots called the series of deaths an "unprecedented tragedy" and offered his condolences to the families.

Three fatal fires in the course of one week is an unprecedented tragedy in Northern Ireland.

Health Minister Edwin Poots

Mr Poots said: "I offer my sincere condolences to the families and friends of the three elderly people who have lost their lives in these dreadful circumstances.

"Everyone should ensure they have a working smoke alarm, which alerts you at the earliest stage of fire, giving vital time to escape. You should also check both your home and workplace for potential hazards, in order to minimise the risk of fire and the potentially horrific consequences."

Dale Ashford, Assistant Chief Fire Officer, said: "It's the third in a week but one would be too many for us.

"If you have a vulnerable relative, a friend, a loved one, let us know. We will send a crew out and do a free home fire safety check and do everything we can to prevent tragedies like this happening again.

"Every single death like this has a terrible human cost."

"I will be meeting our partner agencies this week to discuss if there are further measures we can take, because by working together we can save more lives," he added.

Mr Ashford said in the past year there have been eight fatalities in accidental house fires, compared to 11 fatalities the previous year.

"However we want to reach a stage where we have no fatalities in Northern Ireland due to accidental house fires and we will continue to dedicate ourselves to that."

The Health Minister added: "I would encourage the general public to keep a check on their elderly and vulnerable neighbours, making sure they have a working smoke alarm and helping them to minimise any fire hazards in their homes."