Palestinian militants are denying an Islamic State claim that it was behind a deadly attack against Israel, saying it was them who killed a female police officer on duty near Jerusalem’s Old City, The Associated Press reports.

IS issued a statement Saturday, June 17, taking responsibility for the stabbing and shooting attacks Friday evening. If true, it would mark the first direct IS action against Israel and the group warned on its affiliate news agency it “will not be the last.”

The Hamas and People’s Front for the Liberation of Palestine militant groups quickly retorted that the three attackers who were killed were their members.

The men were armed with an automatic weapon and knives and carried out near simultaneous attacks at two locations. Police Staff Sgt. Hadas Malka, 23, was stabbed to death.