A medical jet with six Mexican nationals onboard crashed into a busy Philadelphia neighborhood Friday, authorities said, marking another US aviation disaster after a passenger plane and a military helicopter collided midair in Washington earlier this week.

Video footage appeared to show the twin-engine plane descending at a sharp angle towards a residential area, sparking a huge fireball upon impact and showering wreckage over homes and vehicles.

The Federal Aviation Administration (FAA) said the aircraft was a Learjet 55 -- an American-French business jet -- that had taken off shortly before from Northeast Philadelphia Airport bound for Branson, Missouri.

The crash happened just after 6:00 pm (2300 GMT).