Turkish police have reportedly detained eight people over the Istanbul nightclub attack.
It is understood the gunman, who shot dead 39 people and injured around 70, isn’t one of those in custody.
The Islamic State group claims it was behind the attack – in revenge for Turkey’s military involvement in Syria.
Fawaz Gerges, International relations professor with the London School of Economics says it bore all the hallmarks: “It was a strategic attack against a strategic target, well planned, well organised, both symbolically and politically very significant.
“There is all out war between ISIS and Turkey since Turkey has fully joined the US coalition against ISIS.”