A third man has been charged after a police officer was allegedly stabbed in Sydney.

The 21-year-old man was released from hospital last night and taken to Blacktown Police Station where he was charged with affray, being armed with intent to commit an indictable offence, possessing a knife in a public place and intimidation.

He was refused bail and was expected to appear in Parramatta Local Court today.

Two other men, Anau Majok, 18, and Musa Musa, 20, were charged yesterday with a range of offenses and remain before the courts.

The alleged incident began after police received a report that five men were fighting in Hill End Road in Doonside at around 12.30pm yesterday.

Four men allegedly fled the scene in a hatchback, while a fifth man fled on foot.

Police, who initiated the pursuit, said Musa was found on foot in nearby Kilto Road.

He was allegedly armed with a knife and stabbed 34-year-old constable Sasha Antic in the chest and back.

Antic continued the arrest despite his injuries, and Musa was taken into custody and charged.

Police pursuing the hatchback were forced to stop after it crashed into a pole on Power Street and four men believed to be inside fled the scene on foot.

Officers ran after them and managed to arrest Majok and a 21-year-old man, who was charged today.

Antic was taken to Westmead Hospital yesterday in a serious but stable condition.

He was released from hospital last night and is expected to make a full recovery from his injuries, police said today.

“He’s in good spirits and keen to get back to work,” NSW Police Assistant Commissioner Gavin Wood said of Antic yesterday.

Police are searching for the remaining two men today. 

Anyone with information about this incident is urged to call Crime Stoppers on 1800 333 000.