Defendants escorted by gendarmerie arrive at the court for their trial in Sincan district, Ankara, capital of Turkey, on Aug 1, 2017. [Photo/Xinhua]

ANKARA - A key trial over Turkey's coup attempt last year started under heavy security measures in Ankara on Tuesday, with 486 suspects accused of masterminding the coup facing justice.

The largest coup trial, which concerns prominent figures of the coup that shocked Turkey on July 15, 2016, started at an exclusively-built courtroom in the suburban Sincan neighborhood.

Most of the suspects are former military personnel at the Akinci Air Base, which was used as the command center by plotters during the foiled coup.

They are charged with crimes ranging from "violating the Constitution, attempting to assassinate the President, attempting to abolish the government of Turkey, managing an armed terrorist organization, seizing military bases, manslaughter, attempting manslaughter and deprivation of liberty."

The key suspect is Fethullah Gulen, a US-based cleric, who is accused by Ankara of being behind the coup attempt. Former air commander Akin Ozturk, a four star general, is among the suspects being tried.

When the suspects guarded by gendarmes arrived at the courthouse, relatives of victims of the coup threw ropes toward them, shouting "death to traitors," as footage from news channels showed.

Established in 1960 in a distant suburb of Ankara, the Akinci Air Base was closed down after the coup and changed its name to Murted Base Command.

After the coup attempt, Turkey declared a state of emergency that is still in effect and launched a massive crackdown against suspected Gulen followers, which soon spread to all opposition circles against the Turkish government.

More than 50,000 people have been arrested over suspected links to Gulen, with hundreds of soldiers sacked or incarcerated.

Events at the Akinci base were at the center of the coup attempt, because Chief of General Staff Hulusi Akar and several army commanders were taken to the base and held captive by pro-coup soldiers during the July 15 coup night.