The explosion ripped the roof and front off the single-storey home above the River Tyne in Marian Court, Gateshead.
Police were attending with an engineer and paramedics were on stand-by after a strong smell of gas was reported in the area.
The elderly occupant of the house was being led away by a paramedic wearing protective gear when the blast occurred.
The paramedic shielded the pensioner from the worst of the blast force, a North East Ambulance Service (NEAS) spokesman said.
Three police officers who had got the man out of the small property were hit by the explosion, as was a gas engineer.
The NEAS spokesman said: “There were three police officers injured, two of whom have burns to the head and forearms, and one of them has more severe burns to his face and is in a more serious condition.
“The gas engineer had minor burns.”
The officers, paramedic, engineer and elderly resident were taken to the Royal Victoria Infirmary in Newcastle for treatment.
Northumbria Police said the injuries were not life-threatening and the injured officers’ families have been informed.
Debris from the blast, including glass, roofing materials and the man’s curtains, was thrown up for 60ft on to a lawn in front of the property.