Up to 30,000 people turned out to watch the annual bonfire celebrations in Lewes where effigies of politicians have gone up in flames.
Sussex Police said 70 people were treated for mostly minor injuries.
There were three arrests for alleged drugs and public order offences and four fixed penalty notices were issued for discharging a firework in public.
Six bonfire societies, known for burning images of high-profile politicians, staged the annual event.
Lewes Borough Bonfire Society (LBBS) created a “ghost train”, targeting rail operator Govia Thameslink (GTR).
The society tweeted: “The LBBS are full steam ahead unlike [GTR] who are not stopping at Lewes tonight.”
Lewes was one of the towns hit by major disruption during a prolonged dispute between Govia Thameslink and the unions over railway working practices.