Sussex Police assistant chief constable Steve Barry has confirmed the death toll could still rise, after a Hawker Hunter jet performing a stunt display crashed onto the A27 following a failed loop manoeuvre.
The plane exploded into a fireball as it fell into moving traffic.
Worthing United footballers Mathew Grimstone and Jacob Schilt, both 23, who were on their way to play a match, are among the dead.
Pilot Andy Hill was pulled from the wreckage and is in an serious condition in hospital.
Steve Barry said: "There are victims that we have in the cars, on motorbikes, pedal cycles and in the seated areas so it makes it very complicated to establish who was where and who we can actually confirm has been a victim of this crash."
"It's probably going to be days rather than hours until the road is fully cleared open again."
So far the death toll is thought to be around 11.
The Civil Aviation Authority (CAA), said it would examine the circumstances of the crash to see whether improvements could be made to current safety requirements.
In a statement it said: "We immediately commenced our review processes and remain committed to continuously enhancing the safety of all civil aviation and will provide further updates in the days to come."