A gang of bikers has caused traffic chaos during a Halloween “ride out” on a busy city road.
The group of around 50 off-road motorcycles and quad bikes brought Kirkstall Road, a major route into Leeds, to a standstill earlier.
Witnesses posted videos on Twitter and described the scenes as being similar to those in the Mel Gibson film Mad Max.
Police closed the road until the group had dispersed.
Videos posted online show bikers riding in convoy, with some pulling wheelies. Others can be seen riding on the pavement.
There were also reports of vehicles being driven around pedestrianised parts of Leeds city centre, according to some witnesses.
The main road was believed to have closed for around 90 minutes while drivers on other roads around the city also reported similar problems.
A police helicopter also attended the incident, which was described by Twitter users as “madness” and “utter chaos”.
West Yorkshire Police confirmed the event had been organised on social media and the road was closed in order to resolve the situation.
Councillor Lucinda Yeadon, deputy leader of Leeds City Council, said police had identified “key individuals” and that some arrests had been made.
In a series of tweets she said: “Some arrests have been made and (police) expect significant arrest activity over the next few days.”
Ms Yeadon said the event had been organised by an individual who is being sought by police.
On Sunday, the Met Police arrested eight men for failing to stop during a similar “ride-out” in London.
Officers used tyre deflation devices to stop 17 motorbikes and three quad bikes.