The deaths of two young boys and a girl in an incident at an Edinburgh flat are being treated as suspicious by police.
A woman who is thought to be the children's mother was taken to the city's Royal Infirmary after apparently falling from the building.
Initially it was thought the children had died in a gas explosion - fire crews had extinguished a small fire at 166 Slateford Road just after 1500 BST.
The identity of the primary school-aged children has not been released.
Lothian and Borders police confirmed a criminal investigation was under way.
The woman, who was found injured on the ground outside the property, remains in hospital.
A Lothian and Borders police spokesman said there had been a fire on the first floor of the three-storey modern apartment block.
Gas supply at the scene was isolated as a precaution, and Scotland Gas Networks engineers were sent to the scene.
However, it was later confirmed that there was not a fault with the gas supply to the flat.
Several foreign students living in the terraced block said they believed the injured woman lived in the property with her three children, and that they were newcomers to the building.
Some said they believed the woman had jumped from a balcony.
Chemical engineering student Moe Harbi, 22, from Saudi Arabia, said he smelt gas at about 0100 BST on Wednesday.
He added: "I thought it was from my flat though I checked the kitchen and the oven and then I slept. I didn't think it was from my neighbours."
Omar Barifah, 20, also a student, told BBC Scotland he had heard a noise "like a shooting gun".
He added: "It felt like a big bang - it was absolutely frightening and I had to take my little brother, and his friend who was sleeping and woke up because of the noise, and we ran out of the house.
"We saw a woman lying on the ground. She was covered by a sheet, then she was taken in an ambulance and we were asked to move to a safer area."
A spokesman for Lothian and Borders Fire and Rescue said: "Two fire appliances and a turntable ladder attended at the address, a three-storey modern townhouse. Two firefighters wearing breathing apparatus extinguished a small fire on the first floor of the building.
"Gas at the property was isolated as a precaution and fire crews remain at the scene with the fire investigation unit - they are currently liaising with the police."
The spokesman said there was "no significant structural damage to the building" and confirmed that the fire was extinguished very quickly.
Ann Fairbairn, of Tallulah Hairdressing on Lanark Road, which joins on to Slateford Road, said: "The road has been cordoned off and it's swarming with police, nobody is allowed in or out.
"There are ambulances, police and it looks like CID as well as the fire service."
Edinburgh City Council leader Jenny Dawe said: "Although there is little information at the moment this is obviously a terrible incident and our thoughts go to those who are affected.
"The council will provide whatever support the emergency services require as they deal with the incident and its aftermath."
Police said westbound traffic was being diverted at Longstone Garage and eastbound drivers are being diverted at Chesser Avenue.
There are also warnings of heavy traffic on the A71 Gorgie Road.