Salman Rushdie

Zafar Rushdie said his father had sustained life-changing injuries, but was able to speak to his family.

Rushdie, 75, was left severely injured after being stabbed on stage at an event in New York state.

He has faced years of death threats for his novel The Satanic Verses, which some Muslims see as blasphemous.

The man charged over Friday's attack has pleaded not guilty to attempted murder.

"Following the attack on Friday, my father remains in critical condition in hospital receiving extensive ongoing medical treatment," Zafar Rushdie tweeted.

The Booker Prize winner, 75, was speaking at an event at the Chautauqua Institution at the time.

New York State Police said a man ran up onto the stage and attacked Mr Rushdie and an interviewer.

Police detained a suspect named as Hadi Matar, 24, from Fairview, New Jersey.

No motive or charges have yet been confirmed by police.

Mr Rushdie was stabbed at least once in the neck, and at least once in the abdomen. He was taken to a hospital in Erie, Pennsylvania, by helicopter.

The writer has been undergoing surgery, police and his agent confirmed.