Turkey has formally asked the US to arrest cleric Fethullah Gulen on charges of orchestrating July's failed coup.

More than 270 people were killed in an attempted overthrow of the government, led by some sections of the military.

In the following weeks, Turkish authorities detained tens of thousands of people suspected of being involved in the failed attempt.

Since the coup, Turkey's President Recep Tayyip Erdogan has blamed self-imposed exile Gulen, 75, and members of his religious movement for orchestrating the coup - something he denies.