A trial has begun in Turkey against dozens of suspects, including the alleged shooter in the New Year's Eve attack that left 39 people dead in Istanbul.

Fifty-seven suspects, mostly foreigners and 51 of them behind bars, were on trial Monday on the outskirts of Istanbul.

Albulkadir Masharipov — the lead suspect — is charged with membership in a terror group, murder, attempting to overthrow the constitutional order, among other charges. The prosecutor is seeking multiple aggravated life sentences.

On Jan. 1, an assailant shot his way into Istanbul's Reina nightclub where hundreds were partying. The assailant escaped and the Islamic State group claimed the attack. Masharipov was caught 15 days later.

Turkey has been hit by a string of attacks since 2015, blamed on Kurdish militants and IS.