The trial of Egypt's former leader Mohamed Morsi and 14 others has been halted because of the defendants' chanting.

The adjournment - on the first day of the controversial trial - is likely to last until later on Monday and comes after a two-hour delay to the start of proceedings.

Security officials said the delay was caused by Mohamed Morsi not wanting to change into prison uniform, part of his refusal to recognise the trial's legitimacy.

Some 20,000 police officers have been deployed to maintain order as Morsi goes on trial accused of inciting the deaths of protesters outside the presidential palace in December 2012.

Egypt's first democratically-elected president could face the death penalty or a life sentence if found guilty.

Morsi's Muslim Brotherhood supporters accuse the army-installed government of fabricating the charges and have called for anti-military protests, raising fears of new clashes.

Hundreds have gathered outside the trial to support him.

Morsi, who has been held by the army at a secret location since he was ousted on July 3rd, was flown to the police academy in east Cairo earlier today for the start of the trial.

Tahrir Square, the main site of protests in the past, was sealed off ahead of the trial by army vehicles and barbed wire.

Morsi's Islamist Muslim Brotherhood gained power in elections after the 2011 uprising against former president Hosni Mubarak.

Millions of Egyptians soon grew disillusioned however, and took to the streets this summer to demand his resignation.

The army - whose regime now runs the country - removed him from power, saying they were responding to the will of the people.