Four family members, including two children, who died following an arson attack on their home in County Waterford have been named locally.

Kim English, Philip English and their children, 12-year-old Callum and nine-year-old Jayden, died in the house fire on Birch Avenue, on the outskirts of Waterford in the Republic of Ireland.

A “multiple murder” investigation has been launched by gardaí (Irish police) following the blaze.

Two other children remain critically ill in hospital following the fire, which was reported shortly after 05:00 local time on Tuesday.

In a tribute posted to social media on Tuesday evening, local football club Johnville FC, where Callum played, said they were “absolutely heartbroken and devastated by the tragic events”.

“Kim and Philip were familiar and friendly faces around our club, always there supporting Callum at his matches.

“It is incredibly difficult to comprehend that a family we knew so well has been taken from us in such tragic circumstances.”

Ending their statement, the club said: “From everyone at Johnville FC, we send our love and deepest condolences to all those affected. You will always be part of our club family. RIP Kim, Phillip, Jayden and Callum.”

Addressing the media outside Waterford Garda Station on Tuesday afternoon, Ch Supt Anthony Pettit said officers believe the house “was attacked by a person or persons unknown and that the fire was started deliberately”.

“The house at Birch Avenue has been declared a crime scene and is currently subject to a technical examination by the Garda Technical Bureau,” he added.

The officer said the four bodies have been removed from the scene and post-mortem examinations would be carried out at University Hospital Waterford.

The two injured children are being treated at a hospital in Dublin.

Firefighters, ambulance staff and gardaí all responded to the emergency at the family home in the Birchwood housing estate, about 3km (1.8 miles) outside Waterford city centre.

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

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

A senior investigating officer is leading the murder inquiry, which is being coordinated from an incident room at Waterford Garda Station.

Family liaison officers have also been appointed to the bereaved family.

Addressing reporters, Ch Supt Pettit appealed for witnesses to what he described as a “multiple murder and arson attack”.

“In particular gardaí wish to speak to anyone who was in the vicinity of Birch Avenue, Birchwood, between 04.30am and 05.30am this morning,” he said.

“Gardaí are also appealing to anyone who was driving in the vicinity of Birchwood, or the adjoining roads, between 4.30am and 5.30am this morning, who may have dashcam footage or images to make such footage available.”

Amy Maguire, who is the manager of the Butler Community Centre, told Irish broadcaster RTÉ News, external that there is a lot of “shock and disbelief” running through the entire community.

Maguire said they opened their centre earlier on Tuesday as a hub for the community to gather, offering tea and coffee. The nearby Sacred Heart Resource Centre also offered liaison and counselling services.

“You know, this is a tight-knit community, it’s a small community and, as the local centre, it’s our job to ensure that we look after the community. So, as long as they need us, we’ll be there,” Maguire said.

“Local butchers have donated sandwiches, we’ve had local companies donate tea, coffee, beverages, snacks, crisps, sandwiches, everything, as well as services.”

The National Educational Psychological Service (NEPS) has also contacted and visited schools in the area to support staff and communities affected by the fatal fire in Waterford.

A spokesperson for the Department of Education said NEPS, which acts as the department’s frontline responder, had been providing support and advice to school management and staff “to support the management of the situation, as the impact of the incident unfolds”.

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

In a statement, he said: “Our hearts go out to the families who have suffered such unimaginable loss.

“We stand in solidarity with all those whose lives have been devastated”, he added.

He said the Catholic Church would “reach out as best we can” to help those affected and the parish priest would minister to the bereaved family and support the local community.

The Diocese of Waterford and Lismore has also since confirmed that a vigil will be held at Sacred Heart Church on Wednesday.

In a post on social media, the Diocese of Waterford and Lismore said the vigil will provide an opportunity for people to “come together in prayer for those who have lost their lives, their grieving families and loved ones, and all those affected by this terrible tragedy”.

Local parish priest, Fr Gerry Chestnutt, said the family will be supported by the community.

“Some of the children went to our primary schools so they will have lots of friends and parents of friends, they will rally around, while this is a big parish, around this area is very tight knit,” he told RTÉ.

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.

Justice Minister Jim O’Callaghan has described the arson attack as a “brutal and heinous act” and insisted those responsible would “face the full rigour of the law”.

“This shocking event has had a very significant impact not just on the people of Waterford but on the whole country,” he said.

“There is no place in a civilised society for such a heinous act of violence.”

O’Callaghan said the murder inquiry was being supported by the National Bureau for Criminal Investigation.

He expressed his condolences to the family and friends of the bereaved and to the two children in hospital.

The housing estate is just off the Killure Road on the outer edge of the city.

Sinn Féin’s David Cullinane, who represents Waterford in the Dáil (Irish Parliament), 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.”

His party colleague, Sinn Féin councillor John Hearne, also knows the family and described it as a “terrible tragedy”.

Hearne told BBC News NI that residents living in the estate noticed the blaze at about 05:00 and they went out to wake up their neighbours to try to help.

But he said it “all happened so fast” and was “hugely distressing for everyone involved”.

Independent councillor Donal Barry had also been working with the family very recently.

Speaking to the BBC’s Evening Extra programme, he was audibly upset by their deaths.

“Only last Thursday I was speaking to Kim on the phone in relation to a matter I was dealing with,” he said.

“As soon as I went up there this morning and I looked and saw the house, my heart sank. I knew who it was then.”

Barry said the immediate family were “well thought of” in Waterford and the community has been “numbed” by the attack.

The councillor added that there was “devastation” in local schools where the couple’s children were pupils.

He praised the efforts made by the local council which set up a support hub at Butler Community Centre in St John’s Park in the aftermath of the attack.

“Waterford City and County Council won’t be found wanting in any support which they can give the community,” he said.