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.

British punk-rap duo Bob Vylan led chants against the Israeli military in a live BBC broadcast on Saturday. Irish-language rappers Kneecap also are being investigated.

British police are reviewing videos from the Glastonbury Festival after rapper Bobby Vylan of Bob Vylan led chants of “death to the IDF” or Israel Defense Forces and “free Palestine” on Saturday.