Erdogan threatens to 'chop off' traitors heads during Turkey coup attempt anniversary speech

Turkish President Recep Tayyip Erdogan has vowed to "chop off the heads of traitors" during an incendiary speech to mark the first anniversary of a failed attempt to overthrow his government.

Erdogan also called for suspected coup plotters to be forced to wear orange jump suits in court.

The notorious outfits were made famous as the uniforms for Guantanamo Bay detainees and worn by hostages held by al-Qaeda and Islamic State group militants in Iraq and Syria, who were eventually murdered by their captors.

"First of all we will chop off the heads of those traitors," Erdogan told a crowd of supporters in Turkey's largest city Istanbul.

"I spoke to the prime minister and... when [the suspects] appear in court, let's make them appear in uniform suits like in Guantanamo."

Turkey held events to mark the one-year anniversary of the failed 15 July putsch on Saturday.

More than 100 people were killed when elements of the Turkish military attempted to overthrow Erdogan and his Justice and Development Party government.

Turkish troops fought back and civilians took to the streets of major cities to help the government regain control. 

Since this, thousands of suspected coup plotters have been rounded up and many more sacked due to their alleged links to exiled anti-Erdogan cleric Fethullah Gulen who Ankara says was behind the coup plot.

The arrests have sparked outrage from human rights groups and the EU, who have been particularly critical of the president's calls for the reintroduction of the death penalty.

Erdogan once again used the rally as a chance to reiterate his support for the execution of "traitors".

"We are a state governed by rule of law. If [law to reintroduce death penalty] comes to me after parliament, I will sign it," he said.

"[The coup] is a shame, this is an immorality," Erdogan said. "This is a disrespect, an insult to our people."