Hours after the attack on Mr. Rushdie, who was stabbed about 10 times as he prepared to speak at the Chautauqua Foundation, Ms. Rowling tweeted her condolences. She initially wrote on Twitter, “Terrible news,” then added: “Feeling very sick right now. Let him be well.”
In response, a user with the handle @MeerAsifAziz1 replied: “Don’t worry, you’re next.”
The tweet was later deleted, though the account remained active as of Sunday afternoon.
A Police Scotland spokesman said authorities had received a report of an online threat against Ms Rowling and an investigation was ongoing.
On Saturday, Ms Rowling, 57, who wrote the award-winning ‘Harry Potter’ books, blasted Twitter for allowing the social media account that made the threat to remain active.
“@TwitterSupport Those are your instructions, right?” she wrote “Violence: You may not threaten violence against a person or group of people. We also prohibit the glorification of violence…”
Twitter did not immediately respond to a request for comment.
On Sunday, Warner Bros. Discovery, the entertainment company behind the “Harry Potter” film adaptations, offered a statement condemning the attack on Ms. Rowling.
“We stand with her and all the writers, storytellers and creators who bravely express their creativity and opinions,” the company said in a statement, which also offered condolences to Mr Rushdie and his family.
“The company strongly condemns any form of threat, violence or intimidation where opinions, beliefs and thoughts may differ,” the statement said.
Mr Rushdie went into hiding in 1989, shortly after his novel The Satanic Verses was published. The book, which contained fictional depictions of the Prophet Muhammad, offended many Muslims and resulted in a fatwa, or religious decree, from Ayatollah Ruhollah Khomeini, Iran’s supreme leader, urging Muslims to kill the author. In 1998, the country’s president said that Iran no longer supported the decree.
As Mr. Rushdie prepared to speak at the Chautauqua Foundation, a man, later identified by police as Hadi Matar, 24, of New Jersey, stormed the stage and stabbed him. Mr. Rushdie remains in a hospital in Erie, Pa., and his agent said Sunday that he is recovering.
Mr Matar pleaded not guilty to the attack.