Many people have been wounded in an attack on a nightclub in Istanbul, Turkey’s NTV reports.

NTV said around 20 to 30 people may have been wounded in the attack, which took place in the Reina nightclub, in the Ortakoy area, at about 01:30 local time (23:30 GMT).

The channel says two attackers were involved, while CNN Turk reported they were dressed in Santa costumes.

Unconfirmed reports say one attacker may still be inside.

Istanbul had been on high alert for any terror attacks, with some 17,000 police officers on duty in the city.

There were reportedly several hundred people in the nightclub at the time. BBC