A match official has been taken to hospital after he was injured following crowd trouble at an NRL game between Canterbury Bulldogs and South Sydney Rabbitohs.
Bulldogs supporters threw plastic bottles at officials as they left the pitch after Friday's 18-17 defeat to their rivals, following a controversial late penalty that won the game for the away team.
Referee Gerard Sutton awarded a penalty against England international James Graham for a late tackle on Adam Reynolds, which was duly kicked by Bryson Goodwin with just two minutes remaining.
New South Wales police have arrested two people on suspicion of assault and have identified a further two for allegedly throwing bottles.
The match is a replay of last year's Grand Final which South Sydney won.