LONDON - For the second time this week, people around the world expressed shock at President Donald Trump inflaming racial tensions after his supporters responded to his attacks on Rep. Ilhan Omar, D-Minn., a Somali-born Muslim, with frenzied chants of "Send her back! Send her back!"

The jarring scene, which followed Trump falsely claiming Omar had praised al-Qaeda, inspired the hashtag #IStandWithIlhanOmar on social media and was trending in the United States on Thursday, along with many other countries including the United Kingdom, Canada and Egypt.

Politicians in Europe took to Twitter and warned that the display at the North Carolina political rally had veered into dangerous territory.

"This is what fascism looks like. We must fight it at home and abroad," tweeted Jess Phillips, a Labour party lawmaker in the United Kingdom.

"Jesus, what next?" asked British politician Emily Thornberry, while David Lammy said the footage was "chilling," adding that "Fascism spreads like wildfire. Especially when it comes from the President of the United States of America."

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Ireland's foreign minister, Simon Coveney, shared a video Trump speaking and the crowd chanting, also calling it "chilling" and adding: "fueling hatred based on race is not acceptable in political discourse... history tells us where this leads!"

On Thursday morning, Democratic support for Omar continued to roll in, as Trump's targeting of the congresswoman entered its fifth day.

Earlier in the week, Trump sent out a series of racist tweets targeting Reps. Alexandria Ocasio-Cortez of New York, Ayanna Pressley of Massachusetts, Rashida Tlaib of Michigan and Omar - telling them to "go back" and fix "the crime infested places from which they came."

The crowd at President Trump's "Make America Great Again" rally in Greenville, N.C., on July 17 chanted "send her back" as Trump spoke about Democratic Rep. Ilhan Omar (Minn.), who has been feuding with the president along with three other minority congresswomen after Trump's racist tweets. (The Washington Post)

On Twitter, Rep. Jackie Speier, D-Calif., linked Trump's specific attacks on Omar to a longer trend of the president making degrading comments on women such as "lock her up" and "blood coming out of her whatever."

"But nobody has more respect for women? #IStandWithIlhanOmar" she tweeted.

TWEET: Jackie Speier 07/18/19

While Republican reaction was muted, social media users and celebrities once again condemned Trump's remarks and expressed their support for Omar.

The Merriam Webster dictionary tweeted late Wednesday evening that searches for the definition of racism and xenophobia were spiking.

Dozens of British politicians and 14,000 supporters signed a letter of solidarity addressed to the four Democratic congresswomen who have found themselves at the center of a fierce political storm.

"We are disgusted by Donald Trump's attack on you. His blatant, unashamed racism has appalled people around the world," the letter stated. "Thank you for showing the world that America can still provide leadership to be proud of, even when the White House has abdicated that role."

London's first Muslim mayor, who has himself been the target of Trump's ire, signed the open letter along with leader of Britain's opposition party, Jeremy Corbyn.

On Instagram, the #IStandWithIlhan hashtag had been used thousands of times.

Rapper Cardi B voiced her support by posting a photo of a grinning Omar on Instagram accompanied by a Beyonce-inspired caption.

Actresses Susan Sarandon and Piper Perabo tweeted that they stood with Omar, with the latter calling her "a good mother, citizen, friend and an important member of Congress."

This article was written by Jennifer Hassan and Kayla Epstein, reporters for The Washington Post.