CAIRO (Reuters/AFP) - Anyone who protests against the Egyptian army on Sunday, when the country celebrates the anniversary of an attack on Israel forces during the 1973 war, will be regarded as agents of foreign countries, a presidential spokesman said on Saturday.

The spokeman, Mr Ahmed al-Muslimani, was speaking to the state news agency in anticipation of demonstrations by the Muslim Brotherhood, which is opposed to the army-backed government.

Supporters and opponents of Egypt's deposed president Mohamed Mursi called for rival demonstrations marking Sunday's anniversary of the 1973 Arab-Israeli war.

The Interior Ministry warned it will "firmly confront" any violence at protests on the 40th anniversary as the authorities tightened security nationwide, state media said.

The Anti-Coup Alliance of Islamist groups led by the Muslim Brotherhood urged its supporters to try to reach Cairo's Tahrir Square, sealed off by the army, to mark the anniversary.