MINYA, Egypt - The Muslim Brotherhood's spiritual leader and more than 680 other people were sentenced to death Monday stemming from last year's post-coup violence in the latest mass trial that was denounced in the West and by human rights groups as contrary to the rule of law.

In a separate ruling Monday, a court banned the April 6 youth group - one of several that engineered the 2011 uprising against longtime leader Hosni Mubarak that set off nearly three years of unrest. It ordered the confiscation of the group's offices.

The sentences for the 683 defendants were announced by Judge Said Youssef at a court session in the southern city of Minya that lasted only eight minutes.

The verdicts are not final and are expected to be overturned. Under the law, once the defendants who were tried in absentia turn themselves in - which is all but 63 of the accused - their trials will start over.

The mass trials were linked to riots in which supporters of ousted President Mohammed Morsi allegedly attacked police stations and churches after security forces violently broke up sit-ins by Islamists in August that left hundreds dead in Cairo. The defendants in Monday's trial are part of a group of nearly 1,000 implicated in the deaths of three policemen and a civilian.

Youssef said he was referring the death sentences - which followed convictions for the violence - to the grand mufti, Egypt's top Islamic official. The move is a legal requirement that is usually considered a formality, but it also allows the judge to change his mind.

Youssef also reduced the sentences against 529 defendants from a mass trial at which he presided in March. He upheld the death penalty for only 37 of them - an extraordinarily high number under Egyptian law - and commuted the rest to life imprisonment.

Amnesty International said it feared the judiciary is "becoming just another part of the authorities' repressive machinery, issuing sentences of death and life imprisonment on an industrial scale."

Washington called for the rulings to be reversed. "The United States is deeply concerned by today's Egyptian court actions," said State Department spokeswoman Jen Psaki.