Police were called at around 8.20am to Highams Park, east London where a double decker bus had collided with the building.
The London Ambulance Service said on Twitter that medics were treating a number of patients at the scene.
Three children and two adults have been taken to hospital after a bus crashed into a shop in north-east London, the London Ambulance Service (LAS) said.
“Officers and London Ambulance Service are on scene.
“A number of people have reported suffering injuries and are being treated at the scene.
“Road closures remain in place around the junction of Selwyn Avenue and Winchester Road.
“Inquiries into the circumstances remain ongoing.”
Paramedics are treating a “number” of people after a bus collided with a building in north-east London, London Ambulance Service (LAS) said.
Medics from the London Ambulance service including a trauma team from the Air Ambulance were treating a number of patients at the scene.
A spokesperson said: “We sent a number of resources to the scene of this incident in Highams Park this morning.
“Working with our emergency service colleagues we treated and assessed 19 people at the scene. Of those 19, we took five people to hospital: three children and two adults.”
“We were called at 8.19am to reports of an incident involving a bus on The Broadway, Highams Park.
“We sent a number of resources to the scene including ambulance crews, advanced paramedics, paramedics in fast response cars, incident response officers and members of our Hazardous Area Response Team (HART). We also dispatched a trauma team from London’s Air Ambulance.
Mayor of London Sadiq Khan said his thoughts were with those affected by the “terrible” incident.
He tweeted: “I’ve received reports this morning of a bus crashing into a building in Highams Park in Waltham Forest. Emergency services are currently on the scene—we will share more information as soon as we have it. My thoughts are with everyone affected by this terrible incident.”
Sir Iain Duncan Smith, the Conservative MP for Chingford and Woodford Green, tweeted: “Thank you to the first responders and emergency teams at the scene.
Eric Garip, 38, told the PA news agency he rushed out of The Corner Cafe after hearing a “big bang” on the opposite side of the road and began trying to carry people out through the emergency door of the bus.
“There were a couple of kids on the floor,” he said.
“We were trying to take the kids out and they were panicking.
“I spoke to the driver and said to come out he said ‘I can’t, I’m stuck.’”
He added: “Some parents were in the bus as well crying.
“I tried to calm them but it was a big shock.
“We went upstairs and told the kids to come out but one was on the stairs so (we) were lifting them.
“They were all scared and crying.”