Some American Airlines pilots were grounded and removed from service for celebrating and US President Donald Trump's ally, Charlie Kirk, in a shooting that caused upheavals in the US political scene.
In a statement, US Secretary of Transport Sean Duffy said:"This behaviour is disgusting and they should be fired. Any company responsible for the safety of the travelling public cannot tolerate that behaviour. We heal as a country when we send the message that glorifying political violence is COMPLETELY UNACCEPTABLE!".
Duffy was commenting on a statement by the carrier condemning violence of any kind and saying,"Furthermore, hate-related or hostile behavior runs contrary to our purpose, which is to care for people on life’s journey. Any such behaviour is unacceptable, and we have already initiated action to address this with our team."
Online vitriol and grassroots persecution have exploded in the wake of the assassination of the 31-year-old who had been an electrifying presence on the US right, with the killing further deepening fraught political divisions in the country.
Kirk, who rallied his millions of followers to help Trump win a second White House term, was both revered and reviled for his pro-gun, anti-abortion and anti-immigrant rhetoric.
His murder has been condemned by both sides of the political aisle. But Trump quickly blamed the country's"radical left," even as authorities were only just launching a manhunt for the killer.
Online trackers have targeted an Oklahoma teacher, who posted on social media:"Charlie Kirk died the same way he lived: bringing out the worst in people."
That teacher has since been investigated by the state's Department of Education, which described his comments as"abhorrent."
'Revolting, unconscionable' comments
Meanwhile, Defense Secretary Pete Hegseth ordered members of the military to identify colleagues who mocked or celebrated Kirk's death.
US Under Secretary of State Christopher Landau declared that"foreigners who glorify violence and hatred are not welcome visitors to our country."
"I have been disgusted to see some on social media praising, rationalising, or making light of the event, and have directed our consular officials to undertake appropriate action," he said in a post on X.
"Please feel free to bring such comments by foreigners to my attention so the @statedept can protect the American people."
Laura Loomer, a far-right conspiracy theorist who has Trump's ear, has been one of the most high-profile attackers of Kirk's critics.
She denounced an employee of the Federal Emergency Management Agency (FEMA), who had expressed disgust on Instagram that flags would be lowered for"the literal racist homophobe misogynist."
Loomer shared the staffer's LinkedIn profile and said: "These people hate us. They don't belong near the levers of our National Power."
