An armed woman in a clown mask has injured several police officers during a high-speed pursuit through western Sydney that only ended after she lost control and crashed into a police car.

The woman, 21, first attracted attention after she allegedly followed another woman into an underground car park at Wentworth Point while wielding a knife.

Pennywise The Clown from the movie IT, based on the novel by Stephen King.

Officers found the woman, who was wearing a clown mask, inside a Hyundai i30 hatchback.

She then allegedly accelerated at police, hitting an officer with her side mirror and a police vehicle before speeding away.