Teenage boy stabbed in Sydney city brawl

A teenage boy has been stabbed in the stomach during a brawl with a group of youths in Sydney's inner city.

The 16-year-old boy was walking with mates on Lee Street at Haymarket when he got into a fight with another group of young males about 11pm (AEDT) on Thursday, police say.

The teenager was stabbed once in the stomach and taken to St Vincent's Hospital with non-life threatening injuries.

Three youths were arrested by police and later released without charge.

"(They were) all juvenile males, they were involved as one of the groups ... we're still trying to determine which group they were a part of," Acting Inspector Stephen Warren told Macquarie Radio.

"They went back to the police station and spoke with investigators and were released."