Two gun­men at­tacked a Han­nukah cel­e­bra­tion on a Syd­ney beach Sun­day, killing at least 11 peo­ple in what Aus­tralian Prime Min­is­ter An­tho­ny Al­banese called an act of an­ti­semitism and ter­ror­ism.

The mas­sacre at one of Aus­tralia’s most pop­u­lar and icon­ic beach­es fol­lowed a wave of an­ti­se­mit­ic at­tacks that have roiled the coun­try over the past year, al­though the au­thor­i­ties didn’t sug­gest those episodes and Sun­day’s shoot­ing were con­nect­ed. It is the dead­liest shoot­ing for al­most three decades in a coun­try with strict gun con­trol laws.

One gun­man was fa­tal­ly shot by po­lice and the sec­ond, who was ar­rest­ed, was in crit­i­cal con­di­tion, au­thor­i­ties said. Po­lice said one of the gun­men was known to the se­cu­ri­ty ser­vices, but that there had been no spe­cif­ic threat.