Boys charged after Sydney party gatecrash

A 16-year-old girl has been treated in hospital after being hit in the head by a brick when a house party in Sydney's east was gatecrashed.

Police say a group of teenage boys jumped a fence at the Kingsford home shortly before 11pm on Friday (AEST), and got into a fight with partygoers.

The 16-year-old girl was not involved in the fight, but was standing nearby and was hit when a piece of brick was thrown.

She was taken to Sydney Children's Hospital where she received stitches.

Police responding to the incident arrested three 16-year-old boys and an 18-year-old who were found nearby.

The 18-year-old has been issued with a notice for trespass and affray, and is due to appear before Waverley Local Court on July 2.

The three 16-year-olds are to be dealt with under the Young Offenders Act for the same offences.