Oscar-winning Australian actress Cate Blanchett was preparing to return to the stage on Thursday after a dramatic mid-performance injury which witnesses said left her with blood gushing from her head.

Sydney Theatre was forced to abandon the rest of a preview performance of A Streetcar Named Desire on Wednesday night after Blanchett, 40, was hit on the head with a prop radio, officials said.

Blanchett fell to the floor on all fours with blood streaming from her head after being accidentally hit with the prop by co-star Joel Edgerton, who plays Stanley Kowalski, witnesses said.

"Cate Blanchett was accidentally struck on the head by a prop. She sustained a minor injury but felt fine soon afterwards," Sydney Theatre Company (STC) general manager Rob Brookman said, labelling it a "minor incident".

"Cate is fine and tonight?s performance will go ahead as planned," he added Thursday.

Blanchett, an Oscar winner for her portrayal of Katharine Hepburn in 2004's The Aviator, is playing fading southern belle Blanche DuBois in the Tennessee Williams classic.

Directed by Norway's Liv Ullman, the show is due to open for a season at Washington's Kennedy Centre late next month.

Theatre-goer Steve Sailah said it initially appeared as though the bloodied fall was part of the script and it was "an amazing real-life performance by her to carry on as if nothing had happened."

"There was no appearance that she'd been hurt at all," Sailah said.

Blanchett finished the scene before the audience was asked to leave the theatre for an early interval due to "technical problems", he added.

"It was only later, once the show had been put on hold, that there was an announcement that a cast member had been injured," said Sailah.

"So a truly great performance by her."

Sky News reported co-star Edgerton had said that the injury "probably looked worse than it was" and Blanchett had not needed to go to hospital.

Source: AFP