Turkish protesters on Monday demanded the death penalty, abolished in Turkey more than a decade ago, for 18 alleged coup plotters on trial for the killing of a military officer who resisted an effort to overthrow the government.

The demonstrators jeered as security forces escorted the defendants into a courthouse in the Turkish capital, Ankara. The crowd also displayed an effigy of Fethullah Gulen, an Islamic cleric based in Pennsylvania who is blamed by Turkey for the failed coup attempt on July 15. The effigy had a noose around its neck. Gulen has denied involvement in the uprising.

Turkey abolished the death penalty as a campaign to join the European Union gained momentum, but President Recep Tayyip Erdogan has said since the coup attempt that Turkey could hold a referendum on reinstating it if parliament fails to pass such a measure. European leaders say any talks on Turkey's bid to join the EU, which faltered years ago, would end if Ankara restores the death penalty.

Relations reached a new low this month because of Turkey's anger over the refusal of some European countries to let Turkish Cabinet ministers campaign for diaspora votes ahead of an April 16 constitutional referendum on increasing the powers of the Turkish president. Supporters of the measure say a more centralized leadership would help Turkey deal with security, economic and other challenges; critics say its approval would fit a pattern of increasingly authoritarian behavior by Erdogan.

The suspects who appeared in court in Ankara are accused of involvement in the shooting of Omer Halisdemir, an officer who was killed after he shot dead Semih Terzi, a renegade military commander who allegedly tried to take over the special forces headquarters in the capital during last year's uprising by some military units.

Suspect Ahmet Kara, who was Terzi's military aide, testified last month that he was duped into participating in the rogue operation without understanding that it was an attempt to overthrow the government. The defendants, whose trial began in February, face life imprisonment if convicted of murder and other crimes.