Reported injuries include a hip injury, spinal injuries, a collarbone injury, possible leg injuries and cuts and bruises.
The accident happened at the end of a railway line in Richmond, in the city's north-west, about 10:00 local time on Monday (23:00 Sunday GMT).
Photos posted to social media outline the chaotic scenes experienced by passengers onboard the train, with blood seen splattered across the floors.
"My first thoughts are those people who have suffered some sort of injury".
No customers or staff are trapped.
Police and Sydney Trains are trying to determine the cause of the incident.
"We don't believe any of [the injuries] are life-threatening or serious".
"I was straight onto the train as soon as I seen people were injured". There is absolutely blood everywhere, it's a big hit.
Memphis Depay Strikes A Wonder Goal In Last Minute vs PSG
In the second half, Dani Alves saw red for PSG and Memphis finally appeared from the bench with twenty minutes left. Alves was only going to get a yellow card but his angry reaction provoked the referee to give him the red.
One caller to the radio station who saw the crash said there was an "almighty bang".
"It just came straight into the end of the barrier and I just watched everyone in the windows of the train just fly like Superman".
"It's all chaos here", another caller, Steve, told the station.
A planned meeting between Sydney Trains and union bosses has been pushed back to 12.30.
"[But] it's still on the rails, and not derailed", he said.
'Paramedics are now responding to a train incident at Richmond.
"It is obviously very concerning", he said.