An Egyptian court has sentenced 529 members of the outlawed Muslim Brotherhood to death on charges including murder, a defence lawyer said.

The death sentences are a sharp escalation of a crackdown on the movement.

Most of those sentenced were arrested during clashes that erupted in the southern province of Minya after the forced dispersal of two Muslim Brotherhood protest camps in Cairo on 14 August.

Political turmoil has deepened in Egypt since the army overthrew President Mohammed Mursi of the Muslim Brotherhood last July.

Security forces have killed hundreds of brotherhood members in the street and arrested thousands of others.

"The court has decided to sentence to death 529 defendants, and 16 were acquitted," lawyer Ahmed al-Sharif told Reuters.

The ruling can be appealed.

The charges against the group, on trial in Minya since Saturday, include violence, inciting murder, storming a police station, attacking people and damaging public and private property.

Only 123 of the defendants were present. The rest were either released, out on bail or on the run.

The government has declared the brotherhood a "terrorist" group. The brotherhood says it is a peaceful movement.

Human rights groups said the verdict suggested the authorities intended to tighten their squeeze on the opposition.

The Muslim Brotherhood, largely driven underground, responded by calling for the "downfall of military rule" on its official website.

Mohamed Mahsoub, who served as minister of legal affairs under Mr Mursi, described the court's decision "a ruling calling for the execution of justice" on his Facebook page.