A criminal investigation has been launched over performances by Bob Vylan and Kneecap at Glastonbury on Saturday, Avon and Somerset Police have said.

The force said it had appointed a senior detective to investigate whether comments made by either act amounted to a criminal offence after reviewing footage.

A statement added: "This has been recorded as a public order incident at this time while our enquiries are at an early stage."

Speaking in Parliament on Monday after the announcement, Culture Secretary Lisa Nandy called the scenes broadcast "appalling and unacceptable".

Police have not specified which part of Bob Vylan's or Kneecap's set would be subject to the criminal investigation.

It comes after the BBC said it should have cut away from a live broadcast of Bob Vylan's performance, during which the band's singer, Pascal Robinson-Foster, who performs under the name Bobby Vylan, led a chant of "death, death to the IDF [Israel Defence Forces]".

Those comments drew criticism of both the English punk-rap duo and the BBC for its live coverage of their performance.

The corporation said it would "look at our guidance around live events so we can be sure teams are clear on when it is acceptable to keep output on air", and labelled remarks made during the performance antisemitic.

Lisa Nandy told MPs that she immediately called the BBC's director general after the set was broadcast.

She said outstanding questions remain, including why the feed "wasn't immediately cut", why it was broadcast live "given the concerns regarding other acts in the weeks preceding the festival" and what due diligence had been done ahead of deciding to put Bob Vylan on TV.

"When the rights and safety of people and communities are at risk, and when the national broadcaster fails to uphold its own standards, we will intervene," she added, and said she will continue to speak to the BBC in the coming days.

Earlier, broadcast regulator Ofcom said the BBC "clearly has questions to answer" over its coverage, and the government questioned why the comments were aired live.

The organisers of Glastonbury have previously said they were "appalled" by the comments, which "crossed a line".

On Sunday, Robinson-Foster responded to the controversy on Instagram, writing "I said what I said" and a statement in defence of political activism, without addressing his on-stage comments in more detail.

Since then, both members of Bob Vylan, who were due to embark on a tour of America later this year, have had their US visas revoked, it is understood.

US Deputy Secretary of State Christopher Landau wrote on X: "Foreigners who glorify violence and hatred are not welcome visitors to our country."

In response, Bobby Vylan released a video statement on social media on Monday, where he said politicians should be "utterly ashamed" about where their "allegiances lie".

"First it was Kneecap, now it's us two," he said.

"Regardless of how it was said, calling for an end to the slaughter of innocents is never wrong. To civilians of Israel, understand this anger is not directed at you, and don't let your government persuade you that a call against an army is a call against the people.

"To Keir, Kemi and the rest of you, I'll get you at a later date."

Avon and Somerset Police also confirmed the criminal investigation would assess Kneecap's Glastonbury performance.

The Irish-language rap band are known for making pro-Palestinian and political comments during their live performances and have attracted controversy in the past.

Band member Liam Óg Ó hAnnaidh, who performs under the name Mo Chara, was charged with a terrorism offence for allegedly displaying the flag of the proscribed terrorist organisation Hezbollah at a gig. He has denied the charge.

Although there was no live stream of Kneecap's performance, the BBC later uploaded a largely unedited version of the set to its Glastonbury highlights page on BBC iPlayer.