Cinemagoers in Sydney were terror-struck when a group of men charged into a screening of Baywatch and started chanting "Allahu Akbar", the Arabic phrase often uttered by Islamic extremists carrying out a terror attack.

A man burst into the Blacktown Westpoint Hoyts cinema in west Sydney around 8pm (11am BST) on Sunday night (11 June) and started screaming "Allahu Akbar", which means "Allah is greater."

At first people thought it was just "a sick joke", one woman said, but when he was joined by three accomplices panic set in.

"People were on edge, you could hear everyone whispering among themselves. When they came we got straight out," she said.

As she fled the venue, she came face-to-face with the men, who she said were in their late twenties or early thirties and of Indian heritage.

The men ran into another cinema and repeated the phrase before fleeing the scene.

Police searched the complex but found nothing suspicious. A spokesperson for New South Wales police said that they were investigating the incident.

Australia is on edge after a series of recent terror attacks. Last week, gunman Yacqub Khayre shot dead a man and injured three police officers in an Isis-inspired attack, in Brighton, one of Melbourne's wealthiest suburbs. Khayre had an extensive history of violence and had previously been acquitted of plotting an attack at a Sydney military base several years ago.

Australian Prime Minister Malcolm Turnbull said the attack highlighted "the need for us to be constantly vigilant, never to be deterred, [and] always defiant, in the face of Islamist terrorism." He linked Khayre's siege to the terror attack at London Bridge on 3 June, which left eight dead and 48 injured.