Two children are among four people who have died following a house fire in Waterford city in the Republic of Ireland.

Gardaí (Irish police) confirmed the deaths of a man and a woman and the two children following the blaze at a house on Birch Avenue.

Two other children have been critically injured in the incident and they are being treated in hospital.

The fire was reported to Waterford Fire Service at 05:13 local time on Tuesday and it said its crews arrived to a well-developed fire at a two-storey house.

It said a number of casualties were removed from the property before the blaze was extinguished and the scene was handed over to gardaí.

In a statement, gardaí said a senior investigating officer had been deployed to the incident and family liaison officers had also been appointed.

They have appealed to anyone who was in the vicinity of Birch Avenue in the early hours of Tuesday to contact them.

The Taoiseach (Irish Prime Minister) Micheál Martin Martin spoke briefly about the fire as he arrived for a Cabinet meeting in Dublin on Tuesday morning.

He said his thoughts and prayers were with those who died and he appealed to the public to “give space to first responders”.

At the time he said that although he did not yet have the full details it was a “very worrying and deeply disturbing situation”.

The housing estate is just off the Killure Road, about 3km (1.8 miles) outside Waterford city centre.

Sinn Féin TD (member of the Irish Parliament) David Cullinane said he knew the family and said his heart went out to their relatives.

“I’m just utterly heartbroken,” Cullinane said.

“There is such devastation in the housing estate itself but also in the wider community in Waterford city.”

The Bishop of Waterford and Lismore, Alphonsus Cullinan, described it as an “unspeakable tragedy” which had shocked the entire city.

He said the Catholic Church would “reach out as best we can” to help those affected and the parish priest would likely call to offer support.

The bishop said neighbours living in the estate would also have been affected by the incident but he believed they would rally round to help the family.

The mayor of the Waterford Metropolitan District, Lola O’Sullivan, urged people not to speculate about the cause of the fire.

“It upsets me no end to see people commenting on social media about something that they don’t have firm facts on,” she said.

Waterford City and County Council has opened a support hub for people who have been affected by the fire.

It said facilities and refreshments were available at Butler Community Centre in St John’s Park.