Police were called to Airbnb rented properties in Docklands and Werribee during a four-hour period overnight on Tuesday to separate but possibly related reports of 40 youths partying wildly.

At the second property, in Attunga Grove, Werribee, police were called because two 17-year-old girls - who had rented the house using their older sisters' identification - were assaulted after threatening to report the youths for gatecrashing. .

When eight police arrived, they were soon overpowered, and had to call for heavily-armed tactical police, complete with the backing of a helicopter and the dog squad.

What ensued was described as war by several residents, as car windscreens and windows on houses were smashed when the youths used tree stakes and rocks found in landscaped front gardens as weapons.

One officer was injured in the incident.

"The behaviour that was displayed this morning is unacceptable and intolerable," Inspector Marty Allison said.

It later emerged that some of the youths at the Werribee property were wearing linen that had been taken from the Docklands property.

Inside the house, where orange stains from police capsicum spray covered walls and window blinds, someone had scrawled the words "MTS", an abbreviation for Menace to Society, an increasingly prominent western suburbs gang, and "Apex", a gang of greater notoriety.

But the Apex graffiti is being treated by police as insignificant; since the gang sprung into public consciousness after last year's Moomba violence, youths have increasingly referred to it in jest.

Detectives are treating seriously, however, links between the youths involved at these properties and recent incidents at other short-term rentals in Altona and Point Cook.

They are also investigating how the two latest out-of-control parties relate to the Summer Slam basketball tournament, which started in Werribee on Sunday and finished on Tuesday afternoon.

The girls who rented the house in Werribee were from Dandenong, and had stayed at the property because it's close to Eagle Stadium, where the national, 64-team tournament was held.

But Inspector Allison said there was no evidence any of those involved in the trouble had been in Werribee because of the tournament, which he described as an elite competition where players had previously been recruited for the world's premier league, the NBA.

The tournament organiser's did not comment yesterday. The basketball tournament is organised by the South Sudanese Australian National Basketball Association, but the teams contain players from many ethnic backgrounds.

In 2015, when the tournament was held in Frankston, organisers had to defend an incident of 12 drunken youths fighting nearby.

"None of our basketball players were involved in those embarrassing acts. We have never had any bad issues at this event," the organisers said at the time.

Inspector Allison said the cultural backgrounds of those involved in the violence was irrelevant, after suggestions from residents that youths with African backgrounds were being protected by police.

"This is not about ethnicity, it's not about people's background, it's not about religion, it's about their behaviour, so any conversation that goes on around ethnicity needs to be squashed."

Inspector Allison defended the initial police response to the incident, and the fact that no arrests were made.

Residents said they were staggered many of the youths involved could be seen at a bus stop less than 100 metres from the carnage shortly after being dispersed by police.

Inspector Allison called for stricter checks on the identification of those using Airbnb, but the company defended its record and processes, saying it had a zero-tolerance approach.

Consumer Affairs Minister Marlene Kairouz said extreme cases of property destruction were "rightly dealt with by police."

She said the government had introduced reforms to stamp out bad behaviour, including fines for causing damage.

New laws clamping down on unruly short-stay guests have been introduced into the Victorian Parliament but are yet to pass the upper house.

With Benjamin Preiss, Anthony Colangelo