Four people, including a child, have been taken to hospital following an explosion which destroyed three houses.
Emergency crews were called to the Violet Close area of Benwell, Newcastle, at about 00:45 BST.
Eyewitnesses told the they heard a “very loud bang” and saw a “bright flash”, with one describing what she thought was an “explosion”.
Northern Gas Networks said its engineers were at the scene, with people being warned to avoid the area and keep their windows and doors shut.
Emergency services remain on site and road closures are in place on Buddle Road and the surrounding area, Northumbria Police said.
Pictures show three houses along the terrace completely destroyed, with roofs collapsed and firefighters working among the rubble.
Piles of debris can be seen on the street outside.
One eyewitness told Radio Newcastle: “There was a big flash, and I was thinking ‘it’s an explosion’ and then after that I was thinking ‘is it a car or something?’ But after that there was the smell and I woke up my family and we went outside.
“It’s a massive shock, in this area there are many children, many families.”
Others said there was still a “heavy smell” of smoke in the area.
A fire service van marked “search dogs” was seen parked nearby, as were gas specialist engineers.
Meanwhile, vehicle recovery workers have taken away several damaged cars on low-loaders.
The North East Ambulance said it had treated four patients – three adults and one child – and taken them to hospital for further treatment.
The Tyne and Wear Fire and Rescue Service said: “We currently have several firefighting appliances in attendance at a large scale incident.”
Newcastle City Council asked people to avoid the area and told those living nearby to stay indoors and keep windows closed “until further notice”.
An evacuation centre was set up nearby, and the Red Cross was seen handing out items including mobile phone chargers and food.
Meanwhile, a nearby community centre, the West End Women and Girls Centre, said anyone who had been evacuated was welcome to stay there for food, drinks or just a warm place.
Additional reporting by Rebecca O’Neill and Peter Harris.