Fire investigators are testing smoke alarms salvaged from a blaze which killed two people as inquiries continue to find the cause.

The victims, who are believed to be a Latvian couple in their 40s, died in the fire in the attic of a three-storey house, converted into flats, in Cecil Avenue, Great Horton, Bradford, at dawn yesterday.

Their identities were not being disclosed until relatives have been informed.

Officers were last night checking to see if smoke alarms had been working and they were also hoping to interview the 11 other residents who survived and managed to escape despite a mass panic.

Geoff Crossley, Bradford district manager for West Yorkshire Fire Service, said suspicious circumstances had not been ruled out.

He said last night: “Due to the nature of the findings of the crews it could be one of a number of causes so fire investigation work is still in progress to eliminate the causes until we get to the right one.

“We are not ruling out suspicious circumstances.”

He said it could take time to discover whether the smoke alarms were working due to the severity of the fire. “It’s possible the system was working in some parts of the building but we don’t know if it was in all the flats,” he said.

Fire investigation officer Stephen Fealy described firefighters being confronted with a “mass panic” as they arrived and people tried to escape from the building at about 6am. At the height of the blaze there were more than 20 firefighters at the scene and an aerial appliance was brought in.

Despite the nature of the evacuation an initial investigation has ruled out any breaches of fire regulations in the house, which had been converted into ten flats.

Fire safety officer Jack Riley said: “Under the circumstances we have got here there is nothing to lead us to believe there has been any breach of regulations.”

Forensics were still at the scene last night, and taking photographs from a house opposite.

Fire investigators were also examining the outside of the third floor.

From the outside of the attic, there seemed to be no indication of the devastation left behind.

A police cordon remained at the lower end of Cecil Avenue with only residents from the other houses being allowed in and out. There was no sign of any of the residents from the sealed-off flats trying to return.

Property owner Janabr Kazi, who lives in Morley Street nearby, said she heard the news on the radio. She said: “I feel bad. My place is a nice place. Only the attic flat is damaged, nowhere else. I am waiting to hear more news.”

Mrs Kazi insisted “everything was right” in the building and said it was “made safe” with two exits and smoke detectors.

She bought the house in 1973 and began to develop it into flats in the 1980s when planning permission was granted – six flats were occupied at the time of the blaze.

Ward Councillor Shakeela Lal (Lab, City) said her heart went out to friends and family of those who died. She said: “It’s shocking and terrible, a sad loss in the community. No-one deserves to die in such a horrific way.”

Roofers who turned up at the house yesterday morning were turned away by police.

Neighbour Imran Majid said: “When I looked out of my window I saw flames then flashing lights from the fire engines. I knew it was going to be bad but I didn’t know anyone had died.”

Councillor Munir Ahmed (Con, City) praised firefighters who tackled the blaze: “They did their job well and I’m sure they will do their best to find out what really happened in there. Whatever happened, it is a big tragedy that two lives are gone.”

Another neighbour said: “We don’t really know the people who live in the flats. We see new faces every few weeks. People come and go there but we still feel great sadness for the people who died and people who knew them.”

e-mail: kathie.griffiths@telegraphandargus.co.uk