An Egyptian court on Saturday sentenced 75 people to death, including top leaders of the outlawed Muslim Brotherhood, for their involvement in a 2013 sit-in protest by Islamists that was broken up by security forces in an operation that left hundreds dead.

In a case involving 739 defendants facing charges ranging from murder to damaging property, the court also sentenced to life in prison the head of the Brotherhood, Mohammed Badie, and 46 others.

Mahmoud Abu Zaid, a photojournalist known as "Shawkan" whose detention has been decried by rights groups at home and abroad, received five years in prison. He was detained in August 2013, meaning that he should walk free within days for time served.

Mass trials of Islamists that yielded dozens of death sentences have not been uncommon in Egypt since 2013, when the military, then led by President Abdel-Fattah el-Sissi, removed an Islamist president who hails from the Brotherhood, which has since been outlawed and designated a terror group.

The trails and death sentences have consistently drawn scathing criticism from rights groups at home and abroad, which have branded the process as a mockery of justice.

On Saturday, Amnesty International condemned the sentences of the latest mass trial, which it described as "disgraceful."

"The Egyptian authorities should be ashamed. We demand a retrial in an impartial court and in full respect of the right to a fair trial for all defendants, without recourse to the death penalty,' said senior Amnesty official Najia Bounaim. The London-based rights group also noted that not a single member of the security forces faced legal proceedings over what it called the massacre that took place when police broke up the sit-in on Aug. 14, 2013.

The sit-in at a square in a Cairo suburb was staged by supporters of Islamist president Mohammed Morsi of the Brotherhood. He became Egypt's first freely elected president in 2012 but was ousted in July 2013 by the military following days of street protests calling on him to step down.

It is widely believed that breaking up the sit-in along with another one across Cairo, also staged by Islamists, left an estimated 900 people dead.

One of Morsi's sons, Osama, was among 22 defendants who received 10-year jail terms on Saturday, while 374 were sentenced to 15 years and 215 to five years.

Proceedings were dropped against five defendants who have died since the trial began.

Saturday's convictions, which can be appealed, are the latest chapter in a crackdown waged by authorities against government critics the scale of which has not been seen in living memory in Egypt.

Since Morsi's ouster, authorities have jailed thousands of Islamists along with some of the secular, pro-democracy activists behind a 2011 popular uprising that forced autocrat Hosni Mubarak to step down after 29 years in power. The crackdown has also enforced tighter controls over the media as well as civil society groups, rolling back most of the freedoms won by the 2011 uprising.