An investigation is underway today after 21 people were injured in a crash on a roller coaster.
One car had got stuck on Blackpool's Big Dipper ride and was then shunted from behind by a following car, police said.
Three people were treated in hospital for facial, back and neck injuries, while 18 others were described by police as "walking wounded".
They were all taken by ambulance to Blackpool Victoria Hospital for treatment following the accident, at around 7.50pm last night.
All 32 of the people on the ride at the time had to be rescued after the cars came to rest around 20ft off the ground.
Firemen employed a specialist rope team and used stretchers and spinal boards to release the trapped victims.
Lancashire Police said it is not clear yet what caused the accident.
A spokesman added: "At this stage it is believed a carriage became stuck on the track part way through the ride and was then struck from behind by a following carriage."
The Big Dipper, a wooden roller coaster, first opened in 1923. It is run by Blackpool Pleasure Beach, which has a number of bigger roller coasters on the same site on the resort's South Shore.
A spokesman for Blackpool Pleasure Beach said: "Investigations are underway to establish the cause of an incident which occurred on the Big Dipper wooden roller coaster on Tuesday at approximately 7.50pm.
"Emergency services attended the incident. There were 32 riders in total.
"The Big Dipper will remain closed while investigations continue but all other rides at Pleasure Beach will open as usual at 10.30am.
"The Pleasure Beach team are working closely with the emergency services and the Health and Safety Executive to establish the cause of the incident."
A spokeswoman for the Health and Safety Executive (HSE) said one investigator had attended the incident last night.
"The HSE is aware of the incident and making preliminary enquiries," she added.