Cheshunt in Hertfordshire also saw police vehichle attacked with fireworks.
Witnesses said a group cruised along Oxford Street and the City pulling stunts on the pavement which saw shoppers and tourists dive for cover.
One woman claimed the bikers were also throwing firecrackers at police and at people’s windows.
A passerby saw a biker from the group “taken down” by police on London Bridge after they laid spike strips across the road.
London Live presenter Reya El-Salahi described how she saw a group of the bikers in Oxford Street at about 8.45pm.
Philip Cane said on Twitter: “Bit of anarchy in Central London as a group of motorcyclists and mopeds in a pack do a [Grand Theft Auto] style drive. Just constant police car convoys too.”
Adam Milford wrote: “At least 500 motorbikes just roared through Blackheath taking up whole road and pavement. What’s that all about?”
Another said: “There’s something very weird happening in the city tonight. Bare people on quad/motorbikes and armed police pursuing them.”
Footage posted online showed police officers arresting one of the riders on London Bridge – which was cordoned off during operation.
A spokeswoman for the Met said: “Police are aware of a ride-out event involving groups of motorcycles and quad bikes taking place across London during the Halloween period.
“On Sunday, 30 October we received reports of a number of these riders engaging in anti-social behaviour.
“Whilst we welcome the use of the public road network we do not tolerate any anti-social or intimidating behaviour.
More than 200 motorcyclists gathered for a "Halloween ride-out" in Solihull and Birmingham on Monday evening, while in Leeds a group of around 50 racing off-road motorcycles and quad bikes brought a busy road to a standstill, police have said.
The riders, many wearing face coverings, sped along roads, jumped red lights, weaved through traffic and "pulled dangerous street stunts".
A police van was attacked, there were reports fireworks were hurled at motorists and one biker suffered chest injuries in a crash with a car.
At least seven people were arrested and 10 motorcycles seized.
West Midlands Police said the injured biker was hurt in a collision in Solihull and was believed to have been riding without lights or registration plates.
It also said a group of bikers also stopped a fire engine from responding to an emergency call and that, at one stage, a group of up to 100 masked bikers surrounded the police van in Yorkminster Drive, Chelmsley Wood, kicking at the wing mirrors and trying to smash its windows.
They sped off when police back-up arrived.
Ch Insp Jack Hadley described the bike gathering, known as a Halloween Ride Out, as dangerous and criminal.
He said: "This wasn't a rally of bike enthusiasts…this was loutish, criminal behaviour.
"Bikers were riding without lights, at speed, dangerously, pulling wheelies in the street, and mounting pavements.
"It is very difficult to plan for outbursts like this: it's not a conventional, planned event and we saw small groups of bikers speeding off in all directions."
Scramblers, mini-motos and mopeds were among bikes seized by police. Early enquiries suggested at least three of the bikes had been reported stolen.
Five men and two male youths were arrested on suspicion of dangerous driving, causing a public nuisance and motoring offences.