UK writer JK Rowling has received death threats on Twitter after expressing condolences to novelist Salman Rushdie, who was stabbed during an event in the Western New York state.

Following the threat, Rowling said that she has filed a complaint with the police.

Rowling, Rowling, who is known for Harry Potter series, expressed condolences to Rushdie by writing "let him be ok" on Twitter.

A Twitter user, who described himself as a Pakistani student and social activist Meer Asif Aziz commented on the post with the words "don't worry you are next."

“Police are involved (were already involved on other threats)," Rowling tweeted on Saturday.

The UK writer also contacted the Twitter support team. But the Twitter support team responded by saying that they see no violations of Twitter rules in Aziz's comment.

On Friday, Rushdie was stabbed twice by 24-year-old man Hadi Matar when he was about to deliver a lecture at the Chautauqua Institution in western New York.

Rushdie's literary agent Andrew Wylie told the media that the author was hospitalized and on a ventilator.

On Sunday, Rushdie was disconnected from the ventilator and is now able to talk. Rushdie is a celebrated India-born British-American author and winner of numerous literary prizes.

In 1989, Ruhollah Khomeini, the supreme leader of Iran at that time, issued an edict calling for the killing of Rushdie, whose book "The Satanic Verses" is considered by many Muslims to be blasphemous.