The trial centres around the Akinci air base which, the government alleges, was the plotters' headquarters.

Defendants will appear in a purpose-built courtroom outside the capital Ankara, facing charges from attempting to assassinate the president to murder.

Rebel soldiers tried to grab power in July 2016, leaving 249 civilians dead.

The trial is the largest yet relating to the coup.

Orders were allegedly sent out from Akinci air base, north-west of Ankara, to bomb parliament as troops attempted to oust President Recep Tayyip Erdogan.

In the aftermath of their botched attempt, thousands of people have been arrested, many suspected of having links to Fethullah Gulen, a cleric living in exile in the US.

Mr Gulen - the chief suspect in the case - is among those being tried, albeit in absentia. He denies the charges.

Critics say Mr Erdogan is using the purge that followed the coup to stifle political dissent.