Hip hop Irish trio Kneecap is being investigated by UK counter-terrorism police after videos emerged allegedly showing the band calling for politicians to be killed and shouting “up Hamas, up Hezbollah”.

It comes after the group, who are vocal critics of Israel’s war in Gaza, came under fire for their pro-Palestinian and anti-Israel messaging at the Coachella music festival last month.

The British police investigation follows widespread criticism of the band’s alleged comments, which led to several of their upcoming gigs being cancelled. Some politicians are also calling for Glastonbury organizers to drop Kneecap from next month’s festival line-up.

Meanwhile, dozens of musicians and artists have signed an open letter supporting the group’s right to freedom of expression.

In recent days, footage has been circulating online that appears to show one of the group’s members shouting “up Hamas, up Hezbollah” in November last year. Separately, video from November 2023 appeared to show one member of the group, who are from Northern Ireland, saying: “The only good Tory is a dead Tory. Kill your local MP.” Tory is another word for Conservative, and MP is an abbreviation of Member of Parliament. In the past decade, two British MPs – Jo Cox and David Amess – have been murdered.

London’s Metropolitan Police Service said in a statement Thursday that it was aware of the footage and that counter-terrorism officers are investigating.

“Both videos were referred to the Counter Terrorism Internet Referral Unit for assessment by specialist officers, who have determined there are grounds for further investigation into potential offences linked to both videos,” the police statement said.

Katie Amess, daughter of Conservative politician David Amess, who was fatally stabbed in a 2021 attack while meeting with his constituents, has called Kneecap’s rhetoric “abhorrent.”

“(It) poses a direct threat to the safety and well-being of elected officials and the democratic institutions they represent,” she said in a statement provided to the PA Media news agency.

Amess commended the action taken by law enforcement and called for those who incite “violence and hatred” to be held accountable.

“As a society, we must stand united against all forms of extremism and ensure that our public spaces, including artistic and cultural venues, are not exploited to propagate messages of hate,” Amess said.

Both videos have been widely circulated online in wake of the band’s Coachella set, where they led the crowd to chant “Free Free Palestine,” criticized Israel’s campaign in Gaza – which has killed more than 52,000 Palestinians, according to the ministry of health there – and also criticized US support for the war.

CNN has reached out to Kneecap’s management for comment.

Brendan Cox, whose wife was stabbed and shot to death in 2016 by a far-right extremist while meeting with her constituents, told Sky News that the band’s apology was “not enough.”

“What’s clear (about the video) is that it wasn’t a joke, that it wasn’t out of context, that it was incitement to violence against members of parliament,” he said. Cox added that Kneecap’s comments “overstepped the mark in a frankly grotesque way,” putting them on the “wrong side of people who might agree with them” on issues, such as Gaza and Northern Ireland.

Since the videos emerged, a string of the band’s scheduled performances have been cancelled.

The group said on X that it would not be performing at Hurricane or Southside Festival this year – two of Germany’s biggest music festivals – and announced three concerts in Berlin, Hamburg and Cologne instead, which have since been cancelled too.

Another concert scheduled to take place at the Eden Project in Cornwall, southwest England, has been cancelled.

Conservative Party leader Kemi Badenoch told ITV News she believes the band should be prosecuted for incitement. “There are people in jail for saying things that are not as bad as what Kneecap have said… they’ve been avoiding justice for far too long,” she told the broadcaster.

Others have come out in support of the group, with several artists signing an open letter calling out the “clear, concerted attempt to censor and ultimately deplatform” the band.

“Kneecap are not the story. Gaza is the story. Genocide is the story,” wrote the band on X, echoing a separate statement of support from Massive Attack.