Breaking news: 35 killed and 40 wounded in New Year's attack on Istanbul night club

ISTANBUL (AP) –  An armed assailant who is believed to have been dressed in a Santa Claus costume opened fire at a nightclub in Istanbul during New Year's celebrations, killing at least 35 people and wounding 40 others, according to Istanbul's governor and Turkey's state-run news agency.

Gov. Vasip Sahin said the attacker, armed with a long-barreled weapon, killed a policeman and a civilian outside the club before entering and firing on people partying inside. He did not say who may have carried out the attack.

"Unfortunately (he) rained bullets in a very cruel and merciless way on innocent people who were there to celebrate New Year's and have fun," Sahin told reporters.

Footage from the scene showed at least six ambulances with flashing lights and civilians being escorted out. NTV said police had cordoned off the area and an operation to capture the assailant was ongoing.

The attack occurred shortly after midnight in the club where an estimated 600 people celebrated New Year's eve. Several shocked revelers were seen fleeing the scene after the attack and the music fell silent. 

The club is located close to recent suicide attacks that killed dozens near a soccer stadium.