Five hurt in crash after chase in Sydney

Five people have been badly injured when their car hit a tree and burst into flames after a police chase on Sydney's north shore.

The driver and four passengers were taken to various hospitals in serious and critical conditions following the smash on Sunday afternoon, police say.

Emergency services were alerted about 4.40pm that a car had left the road and hit a tree in Cammeray.

Police say they had begun then terminated a pursuit with the vehicle shortly before the crash.

Officers helped the five occupants from the vehicle, which had caught alight, and treated them at the scene before paramedics arrived.

Police have launched a critical incident investigation and are calling for witnesses to come forward.