UPDATE: Police say 11 people were arrested during last night's brawl in Charlestown.
26 police cars were called to deal with the estimated crowd of 300 young people.
Two teenage girls were taken to John Hunter Hospital, suffering suspected drug overdoses.
EARLIER: An out of control house party at Charlestown has ended with teenagers brawling with police in the middle of a busy road.
Officers were initially called to a house in Ida Street at 8:20pm following a noise complaint, and found a large group of young people.
As they tried to break up the party, some of the teens lashed out at police throwing bottles and cans resulting in a brawl.
One person ran from police after being capsicum sprayed.
Witnesses say a bystander stopped him by using a shoulder charge, allowing officers to arrest him on Charlestown Road near the Pacific Highway intersection.
A 17-year-old partygoer described the scene as "insane".
She told Hit 106.9 she and her friends were expecting a house party with some high school friends but arrived to something very different.
"There were so many strangers," she said. "There were crazy kids trying to fight police and yelling 'f*ck the cops' as they sprinted across the road."
It's understood "hundreds of kids" were at the scene, with some heard kicking in windows nearby.
A large number of police were needed to deal with the incident, while the Highway had to be closed to traffic. Hours later, squad cars continued to patrol the area as sizeable groups of teens continued to roam the streets.