A female police officer has been killed in a car crash under lights and sirens in Sydney’s inner west.

About 1.30am Friday, a fully marked police vehicle was travelling along north along Gibbons Street, Redfern, when it slammed into a tree.

The passenger in the police vehicle – a female constable – died instantly.

NSW Ambulance paramedics treated the driver – a male constable – at the scene before he was taken to Royal Prince Alfred Hospital in a stable condition.

A crime scene has been established and the incident has been declared a critical incident.

Premier Chris Minns said his thoughts were with the friends, family and colleagues of the officer who had died.

“Every day our police officers put themselves in harm’s way to keep the rest of us safe, and today the entire NSW Police family will be grieving,” he said.

“I’m also thinking of the officer injured in the crash and everyone who responded to this terrible scene.”

Opposition Leader Kelly Sloane said she was “heartbroken” by the news.

“(The officer) was out working while most of us were asleep, protecting the community,” she said.

Police are urging anyone with information about the incident – or with relevant dashcam or mobile phone footage – to contact Crime Stoppers on 1800 333 000.

–AAP