This is the dramatic moment shoppers fled as part of the ceiling collapsed at a shopping centre in Sydney.

Footage captured by Taufa shows sections of the damaged roof with water cascading down as shoppers hurried away inside Lidcombe Shopping Centre on Friday.

Taufa said: 'It was a hot, typical Friday. I was having a casual coffee with a mate when the roof caved in over the food court. Minutes later, the entire building was evacuated.

'Getting our car out was chaos. Drivers were leaving through no exit lanes as police arrived everywhere.'

Local media reported that paramedics treated one person at the scene.

Fire Rescue NSW Inspector Steve Brown said emergency crews were called at around 1:50 pm after an automatic fire alarm was activated inside the Parramatta Road complex.

He added: 'Almost immediately after that activation, triple zero calls began reporting a ceiling collapse and injuries.'

Five fire engines and more than 20 firefighters, including specialist rescue teams, were deployed to the site.

Authorities said the collapse may have been caused by the activation of a sprinkler head in the ceiling space, though the exact cause has not yet been confirmed.

Significant internal flooding was reported, and an investigation is underway.