Four people, including a child, person been taken to infirmary pursuing a "large" occurrence which has destroyed a house.
Emergency crews were called to the Violet Close country of Benwell, Newcastle, astatine astir 00:45 BST.
Eyewitnesses told the BBC they heard a "very large bang" and saw a "bright flash", with 1 describing what she thought was an "explosion".
Northern Gas Networks said its engineers were astatine the scene, with radical being warned to debar the country and support their windows and doors shut.
Emergency services stay connected tract and roadworthy closures are successful spot connected Buddle Road and the surrounding area, Northumbria Police said.
One eyewitness told BBC Radio Newcastle: "There was a large flash, and I was reasoning it's an detonation and past aft that I was reasoning is it a car oregon thing but aft that determination was the odor and I woke up my household and we went outside.
"It's a monolithic shock, successful this country determination are galore children, galore families."
The North East Ambulance said it had treated 4 patients - 3 adults and 1 kid - and taken them to infirmary for further treatment.
The Tyne and Wear Fire and Rescue Service said: "We presently person respective firefighting appliances successful attendance astatine a ample standard incident."
Newcastle City Council asked radical to debar the country and told those surviving adjacent to enactment indoors and support windows closed "until further notice".
At the scene
By Andy Watson, BBC Radio Newcastle
There is simply a sombre ambiance astatine the Buddle Road cordon, families person been waiting determination asking for updates since aboriginal this morning.
People surviving adjacent said they heard a "very large bang".
Some said they thought it had been a car crash, but past their windows flashed orangish with flames and they could odor dense fume successful the area.
Shock seems to beryllium the main emotion astatine the infinitesimal arsenic radical hold to find retired more.
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