A house fire in which three people were killed is being treated as suspicious, police said.
Neighbours described hearing "an explosion" before the blaze at the semi-detached property in Heaton, Bolton, Greater Manchester.
Emergency services were called to the scene at about 2am.
Three fire crews were despatched as firefighters broke into the smoke-filled house and brought out a woman who was taken to hospital but died a short time later from burns.
Two bodies were then found inside following a further search of the address.
The middle-aged couple living at the house were named locally as Mani and Mona Hassan.
It is thought they were Iranian and that an elderly relative may have been staying with them.
A couple who live next door, who did not wish to be named, said they were woken by an explosion, which apparently came from the kitchen area of the property. They then saw smoke fill the building.
Another close neighbour, Maria Taylor, 48, said she was woken by the sound of fire engines and then heard smashing glass as firefighters broke in to gain access to the property.
She said: "There were some flames initially and then a lot of smoke coming from the kitchen area. It was going up the stairwell, up to the landing.
"An ambulance then arrived and a body was brought out. They were doing CPR on the person in the garden at the front.
"The fire was put out pretty quickly."
She said she thought the couple had two children who were away at university.
"They were a lovely, lovely family," she said: "They have lived here for about 10 years. I don't know them well but we would always say hello to each other and exchange pleasantries.
"I think they were Iranian. They have been trying to sell their house for quite a while - I think they wanted to downsize after the children left home."
Stuart Whittle, who lives opposite, said he arrived home in the early hours to a fog of smoke.
He said: "As I got closer I could see fire engines and police cars. I didn't think anyone was in the house."
He said he believed an elderly relative had been staying with the couple.
Bolton Mayor Colin Shaw, who lives in Albert Road West, said: "I am absolutely shocked. We only live down a few doors down the road.
"At about 3.15am the police came and told me what had happened. I understood there was one fatality at the time, so I'm shocked it's now three.
"Time will tell what happened.
"I didn't know them at all. The house has been for sale for some time. I think they were Iranian."
The property was cordoned off as forensic crime scene officers conducted examinations.
Bolton Divisional Commander Chief Superintendent Dave Hull said: "Three people have tragically lost their lives and our thoughts are with their loved ones at this time.
"We have launched a joint investigation with the fire service and experts from both agencies will be working together to find out what happened and why.
"I know people, especially in the local community, will be shocked and anxious to find out what has gone on and as soon as we are able to provide further updates we will do so.
"I do not want to second-guess or prejudice the outcome of these investigations but in the interests of absolute transparency want to make it clear that we are treating these deaths as suspicious and are not looking for anyone in connection with the fire at this time.
"There will be extra officers in the area and I would ask local residents to come and speak to us if they have any information or concerns."
Mrs Taylor said earlier she had not noticed any disturbances at the property while the Hassans lived there.
She said: "There has never been any trouble before. Last night was quiet, like any other night.
"It all feels a bit surreal, like a film."
She said Mr Hassan used to run a computer business in nearby Chorley Old Road, while his wife worked at Next.
There was no obvious fire damage to the outside of the property but it appeared to be smoke-logged inside, with all the windows and doors opened.