Queanbeyan police broke up a party at Jerrabomberra on Friday night which was attended by about 200 people, including gatecrashers.

It is understood the party, which was hosted by a 16-year-old, had been advertised on Facebook.

A large number of people, who were not invited, attended and police were called. Officers had gone to the address several times during the night.

They arrived again at 11pm and dispersed the crowd. Two young people were arrested for minor offences.

A police spokesman said considerable damage was done to the property and police are investigating.

Police also dealt with another party in Queanbeyan on Saturday night which was attended by about 40 people.

Officers attended the party at 11.50pm in response to complaints from neighbours.

Police said that party was also gatecrashed.

Officers dispersed the crowd and one young person was arrested after a fight broke out at the party.

Partygoers also caused damage to neighbours' fences.

The two parties prompted police to warn of the dangers of people advertising parties on social media sites, such as Facebook, and not having appropriate security in place.

Under new West Australian laws, people who organise a gathering of 12 people or more, where two partygoers engage in criminal conduct that is likely to cause fear or alarm or substantial interference to others in the surrounding area, face a year in jail or a $12,000 fine.

Police have also been given tougher powers under the laws which enable them to arrest people who do not obey an order to leave a party which has been declared an "out-of-control gathering".

People convicted of failing to obey such an order face fines of up $12,000 and one year in jail. If they fail to comply with the order and act aggressively or disorderly, they could be fined as much as $18,000 or jailed for three years.