A little girl is among six people feared dead after an air ambulance crashed into a city neighbourhood in Pennsylvania, in the second aircraft tragedy to rock the US in recent days. 

The youngster had been travelling with her mother and four others when their Learjet 55, a type of medical transport jet, crashed into homes in Northeastern Philadelphia. It is understood that the child, who lives in Mexico, had come to the US for the treatment of a life-threatening condition, and was on her way home when tragedy struck.

The medical transport jet exploded in a fireball which has engulfed several homes, with the flight’s operator Jet Rescue Air Ambulance later confirming that sadly there were no survivors from the passengers and crew on board.

In addition, further casualties - and fatalities - are feared among those living in the houses along Cottman Avenue and Roosevelt Boulevard, which is where the deadly crash happened.

Emergency services are currently hard at work in Northeastern Philadelphia, where "an active scene under investigation”, following a major incident declaration issued by authorities at around 6pm on Friday.

Since then, shocked witnesses in the Pennsylvania city have been recounting the terrifying experience. Michael Schiavone, aged 37, heard a loud bang and his house shook. Comparing it to a mini earthquake and when he checked his home security camera footage, he said it looked like a missile was coming down. He said: "There was a large explosion, so I thought we were under attack for a second."

The harrowing incident comes just two days on since a fatal air crash rocked the US, when an American Airlines flight carrying 60 passengers and four crew members collided with an Army helicopter carrying three soldiers, in Washington DC. Sadly there were no survivors.

Follow our live blog below for updates on the Philadelphia crash