CNN host draws criticism from the right after calling Trump a 'piece of s---' over response to London attack

CNN host Reza Aslan faced backlash on Saturday after calling President Donald Trump a "piece of s---" after a terrorist attack in London left seven dead and dozens wounded.

In a tweet on Saturday that was later deleted, the University of California, Riverside professor and host of "Believer" quoted the president's use of several terrorist incidents in London to justify his executive action barring individuals from several majority-Muslim nations.

"This piece of s--- is a not just an embarrassment to American and a stain on the presidency. He's an embarrassment to humankind," Aslan wrote.

The tweet immediately sparked outrage on the right.

Aslan deleted the tweet and apologized Sunday afternoon, saying he lost control when he saw Trump's "derogatory" response to the London attack.

In a statement on Sunday, CNN distanced itself from Aslan, but applauded the host for apologizing.

"Reza Aslan is not a CNN employee, but does host a series on the network," a CNN spokesperson said. "We are pleased that he has apologized for his tweets. That kind of discourse is never appropriate."

Aslan, who is Muslim, has been highly critical of Trump's travel ban, which was halted by a federal appeals court due to a debate over whether it is overtly religiously discriminatory.

The professor went viral for his clash with Trump supporter Kayleigh McEnany last year over the proposed ban as well as Trump's claims that thousands of Muslims in New Jersey celebrated after the September 11, 2001 terrorist attacks, an unfounded assertion.

"Anti-Muslim bigotry has been the hallmark of Donald Trump's campaign throughout," Aslan said.

Trump's response to the incident on Twitter was criticized by many in the UK and on the left who have frequently blasted his occasionally misinformed attempts to blame violent incidents on Islamic extremists.

For its part, CNN has become a frequent target for Trump and the right as the network has ramped up its intrepid reporting on the Trump administration.

This was the second time this week a CNN-affiliated personality enraged the right.

CNN severed ties with comedian Kathy Griffin after she posed with a bloodied prop Trump head.

Though Griffin has a decades-long career in comedy and maintains minimal ties to the network - she has hosted its fairly unserious New Year's Eve special - some on the right labeled her a "CNN star."