A child has died after a massive explosion wrecked a number of houses.
A second person was trapped in the rubble following the blast, in the Shaw area of Oldham.
A third was unaccounted for and a fourth, a man, suffered severe burns in the incident, which is thought to have been caused by a gas leak.
Emergency services described the explosion, which damaged a number of terraced properties, as "very serious".
Superintendent Neil Evans of Greater Manchester Police told reporters at the scene that the child had been confirmed dead.
Supt Evans said: "This is an ongoing search and rescue effort and we are offering our full support to the fire and other emergency services.
"Our main and immediate focus right now is to assist in ensuring those injured in the explosion get any medical assistance that they need."
A spokeswoman for the North West Ambulance Service said one patient had been taken by helicopter to Wythenshawe Hospital in Manchester with 80% burns.
"We are currently assessing the scene and working closely with other members of the emergency services, with our priority being to ensure people receive the medical help they need as quickly as possible," she said.
Greater Manchester Fire Service said more than 30 firefighters were at the scene carrying out a search of the immediate area. Those involved included specialist search and rescue teams, with a dog, and colleagues from Lancashire Fire Service.