A man and a woman have died in a house fire in which four children and another man were injured.
Firefighters were called to the blaze in Withington, Manchester, at about 2.20am on Friday.
A Greater Manchester Police spokesman said a man and a woman died at the scene.
Three girls and a boy, aged between 10 and 17, were taken to hospital, where they are being treated for their injuries.
Another man was also taken to hospital and he remains in a serious condition.
Police have launched a joint investigation with Greater Manchester Fire and Rescue Service (GMFRS) to establish the cause of the blaze.
Detective Inspector Tony Lea said: "My thoughts are with the family of the man and woman after such a tragic incident and we have specially-trained officers supporting the family at this time.
"We are continuing to work closely with GMFRS to establish exactly how this fire started and I urge anyone who may have witnessed the fire, or anyone in the area in the hours before the fire.
"If you have any information at all contact police as soon as possible so we can piece together what happened."
The force spokesman said next of kin had been informed but the bodies had yet to be formally identified and post-mortems had not yet taken place.
Anyone with information should contact police on 101 quoting incident number 140 10/02/17 or the independent charity Crimestoppers, anonymously, on 0800 555 111.
Neighbours said a "quiet and polite" Asian family lived at the address, a detached house on a tree-lined road of semis, formerly family homes, many converted into student houses, around a mile from Manchester University.
The road was blocked off with police tape and police and fire service vehicles stood outside the house, with its smoke-blackened upstairs windows wide open.
Fire and crime scene investigators put on white body suits as they carried on their work, taking photos and carrying equipment into the property.