Some 150 writers, academics and activists - including authors JK Rowling, Salman Rushdie and Margaret Atwood - have signed an open letter denouncing the "restriction of debate".

They say they applaud a recent "needed reckoning" on racial justice, but argue it has fuelled stifling of open debate, the BBC reports.

The letter denounces "a vogue for public shaming and ostracism" and "a blinding moral certainty".

Several signatories have been attacked for comments that caused offence.

That includes Harry Potter author JK Rowling who was fiercely criticised this month for comments about transgender people.

A diverse cross-section of figures from across the globe put their names to the letter which was published on Tuesday in Harper's Magazine.

It includes US intellectual Noam Chomsky, eminent feminist Gloria Steinem, Russian chess grandmaster Garry Kasparov and author Malcolm Gladwell.

Several have had works banned in some countries, including British novelist Salman Rushdie, who lived in hiding after receiving death threats for his 1988 book Satanic Verses.

And at least two novels by Syrian writer Khalid Khalifa that criticised Syria's government were banned in his home country.