Turkish police are hunting for an assailant who – reportedly dressed as Santa Claus – opened fire at a crowded Istanbul nightclub during New Year’s celebrations Sunday, killing at least 39 people and wounding close to 70 others in what authorities said was a terror attack. The attacker, armed with a long-barrelled weapon, killed a policeman and a civilian outside Istanbul’s popular Reina club at around 1:15 a.m. before entering and firing on people partying inside, Gov. Vasip Sahin said.