Canberra: Four people have been arrested after two huge, unplanned Christmas parties involving more than 8,000 people, Santa hats and a lot of alcohol in Melbourne and Sydney.

Five thousand people gathered at Melbourne’s St Kilda beach on Monday afternoon and continued drinking past the local council’s 8pm alcohol ban, trashing the foreshore and resulting in two people being arrested for public drunkenness and assault. A 27-year-old man was hit by a tram in the aftermath, a 27-year-old woman was taken to hospital with alcohol poisoning and several others were injured by stepping on broken glass, police said.

Victoria police inspector Jason Kelly said the unplanned event had “escalated” and left an “appalling, really unacceptable” level of rubbish behind for workers from Port Philip council to clean up.

“What really disappoints Victoria police is the level of intoxication that occurred here tonight as evidenced by the level of rubbish left behind,” Kelly said in a beachside interview on Christmas night.

Kelly said while the beach was open to everyone, the “level of intoxication” was disappointing.

“Overall, considering the number of people here and that we have dispersed them ... it was a significant response from Victoria police to ensure the local safety of the community here,” he said.

The council instituted a 10-day drinking ban on the beach from Boxing Day.

In the Sydney suburb of Little Bay, revellers complained of being pushed and pepper sprayed by police who arrived to break up a gathering of about 3,000 backpackers.

Two women aged 23 and 25 were arrested and charged with assaulting police, who allege the women hit them with bottles.

Footage of the aftermath of the party shows officers attempting to disperse the gathering. Videos from the scene posted online show dozens of people in Santa hats drinking, singing and dancing to loud music.

One man wearing a panda head and carrying a boxed-wine bladder, or goon bag, holds up his middle finger as police officers approach the booing crowd.

One video posted on Facebook showed at least four women being pushed to the ground, including two who landed on the road, as officers doused others with pepper spray.

Stephen Minshaw, who was injured, said police were hitting people with batons as they tried to leave.

“I don’t get why the police needed to use force,” he told the Seven Network. “We’re backpackers, we’re not going to ... fight back against them.”

He denied the party had got out of hand.

Other social media users responded to the footage by labelling the police response “unnecessarily violent”, “ridiculous” and going “way too far”.

A police spokeswoman said she wasn’t able to comment on the videos or police tactics.

Last week Eastern Beaches police posted a warning on Facebook about alcohol-free zones at all local beaches. Randwick city council had introduced tighter alcohol restrictions for Christmas, police said, and anyone who was caught risked a maximum fine of $2,200 (Dh8,074).