British police are reviewing video footage of rap punk duo Bob Vylan’s Glastonbury set after one of the artists led chants slammed by British Prime Minister Keir Starmer as “appalling hate speech.”

British police said Monday that they have launched a criminal investigation into the rap-punk duo Bob Vylan’s weekend performance at the Glastonbury Music Festival over its vocalist’s chants against the Israeli army. Police said they made the decision after reviewing video footage and audio of the performance.

LONDON (AP) — U.K. police announced Monday that the weekend performances by rap punk duo Bob Vylan and Irish-language band Kneecap at the Glastonbury Festival are subject to a criminal investigation after they led crowds in chants calling for “death” to the Israeli military and chants of “Free Palestine.”