Dozens of teenage thugs were pepper-sprayed by police after an all-in brawl broke out on a Melbourne bus in an affluent suburb increasingly plagued by youth crime.

The chaos started when the gangs started terrorising locals in Chelsea, a beachside suburb in the city's south-east to which they commute, at about 9.30pm on Wednesday.

About 30 Victoria Police officers arrived and moved the men away from the beach, shipping them onto a 902 back to Springvale in the city's outer southeast suburbs.

But as they boarded the bus, a brawl erupted between two groups of teenagers.

Police were forced to use pepper spray in an attempt to stop the fight.

Police arrived to Chelsea, in Melbourne's south east, on Wednesday night after reports teens were causing trouble in the streets

The chaos started when the gangs started terrorising locals, before police asked them to move on

The brawling teenagers were dragged off the bus and ended up on Station Street, where police had to cordon off part of the road to traffic.

One of the teenagers was heard saying 'I f**ked her up, I f**ked her up. Say something now, I f**ked her up,' the Herald Sun reported.

Several others screamed that they needed water for their eyes after being pepper-sprayed.

Officers hosed down a group of the teenagers at the nearby police station.

An 18-year-old man was arrested but released early Thursday morning while police conduct further investigations.

The teens started a brawl on a local bus, before police were forced to use pepper spray to break up the fight

Police said they would inquire about his possible involvement in several incidents which occurred during the night.

The incident follows a spate of youth crime in the suburb in recent months.

Last week a fight started outside Chelsea Pizza House and Fish and Chips, where around 12 teens were seen screaming, swearing and kicking each other as terrified bystanders watched on.

In December last year, youths of African background smashed a glass bottle over a teenager's head before assaulting multiple swimmers and stealing their wallets on the same beach.

A male swimmer was assaulted when he confronted the thieves who fled with mobile phones and purses.

The group later approached three other men who were also assaulted.

Moments after, a 19-year-old man who was sitting on the beach was approached by the group of thugs.

He was violently struck in the head with a glass bottle and assaulted with a plastic cricket bat.

Melbourne's Chelsea Beach has suffered a spate of brawls caused by youth gangs in recent years (pictured, brawl from last week)

Police walk among swimmers as they patrol Chelsea Beach in Melbourne's south east

In 2016, a woman suffered spinal injuries after an attack involving up to 10 men of Sudanese appearance at Chelsea beach.

On another occasion, a shopper was kicked and punched by five youths in a Woolworths car park.

A spokeswoman for Victoria Police said officers are investigating youth gang activity on bus lines in Melbourne's southeast.

'We know anti-social behaviour may tend to increase as the weather gets warmer and more people are out and about,' she said.

Fed up locals have voiced their fear on social media, calling on Mordialloc state Labor MP Tim Richardson to step up and do something about the violence.

'Please do something about our once peaceful and safe neighbourhood … we are all scared,' one woman said.