A major police operation is underway following alarming reports of stabbings and a sighting of an armed individual at the Westfield Shopping Centre in Bondi Junction, Australia.

Emergency services swarmed the scene after frantic calls came in, indicating a man wielding a knife within the premises.

Shoppers were swiftly evacuated from the bustling complex as emergency sirens blared, marking a tense situation unfolding in the heart of the city.

Ten victims, including a baby, with four people dead, have been reported so far from the incident.

Witnesses reported chaotic scenes as multiple emergency vehicles descended upon the area while members of the public fled in panic.

Eyewitnesses recounted harrowing moments of fear and confusion, with one individual revealing that gunshots were heard amidst the chaos, triggering the evacuation process.

Details regarding the extent of injuries or the motive behind the incident remain unclear as authorities work to secure the area and investigate the unfolding situation.

The public is urged to avoid the vicinity of the Westfield Shopping Centre as the situation continues to develop.

Two witnesses told 9News Australia they helped a mother with her baby being stabbed, with one of them saying they were "trying to hold the baby and compress the baby and same with the mother, trying to compress the blood".

The other man said: "It was really bad, there was a lot of blood on the floor.

"I hope the baby is alright."

A passer by called the man a "hero", while he replied it was a "very dramatic afternoon".