Controversial atheist British professor Richard Dawkins has provoked outrage in a tweet he made deriding the lack of academic achievements by Muslims.

On Thursday, the best-selling author of “The God Delusion,” tweeted that: “All the world’s Muslims have fewer Nobel Prizes than Trinity College, Cambridge. They did great things in the Middle Ages, though.”

That post provoked a slew of outraged responses, including accusations of “racism,” and “Islamophobia.”

Responding to the fierce criticism, Dawkins retorted in another tweet: “Muslims aren’t a race. What they have in common is a religion. Rather than Trinity, would you prefer the comparison with Jews? Google it.”

In a later tweet explaining why he chose to single out Muslims, he responded: “Why mention Muslim Nobels rather than any other group? Because we so often hear boasts about (a) their total numbers and (b) their science.”

Writing in the UK Guardian newspaper, Muslim author and commentator Nesrine Malik wrote slammed the comments, claiming that whilst  “…it is technically true that fewer Muslims (10) than Trinity College Cambridge members (32) have won Nobel prizes,” the comparison was not a fair one since you could “insert pretty much any other group of people instead of ‘Muslims’, and the statement would be true. You are comparing a specialized academic institution to an arbitrarily chosen group of people.”

“Dawkins is really trying to say… that Muslims as a unit throughout history have done nothing since the Middle Ages,” she concluded.

Dawkins also received criticism from prominent atheists in the UK, including Tom Chivers of The Daily Telegraph, who asserted that he had crossed the line by going beyond criticism of the religion of Islam, which he said was legitimate, “to criticizing Muslims as a vast block.”

But Dawkins also received messages of support.

One Twitter user reacted to the scale of the backlash against the professor by asking “Why do people shriek ‘racist!’ when Islam is criticized even though Islam isn’t a race? It WORKS; it shuts us up. We must stop being cowards.”

Dawkins himself later defended his comments by asserting that “Something you can convert to is not a race. A statement of simple fact is not bigotry. And science by Muslims was great in the distant past.”

The Oxford evolutionary scientist, who has previously described himself as “anti-God,” is seen as extreme by many other atheists for his regular attacks on world religions. In his seminal work “The God Delusion,” he described “The God of the Old Testament” as “the most unpleasant character in all of fiction.”

Much of his previous attacks on religion have focused more on Christianity than Islam, but this is not the first time he had offended Muslims.

For example, in April he mocked British Muslim writer Mehdi Hassan, claiming that he shouldn’t be taken seriously as he believed “that Mohammed flew to heaven on a winged horse.”