At least 50 people were killed and more than 200 wounded after violence broke out across several Egyptian cities on Sunday, according to the country's health ministry.

In Cairo, supporters of the military-backed interim government had turned out in large numbers to commemorate the 40th anniversary of the 1973 Arab-Israeli war. The conflict was followed by a 1979 peace agreement, under which Israel returned the Sinai Peninsula to Egyptian control. Thousands gathered in Tahrir Square, waving Egyptian flags and carrying posters of the army chief General Abdel-Fattah el-Sissi, who helped remove President Mohammed Morsi on July 3.

Clashes broke out when loyalists of the deposed president attempted to converge on the square. Police fired shots and tear gas to disperse stone-throwing protesters.

A total of at least 45 people were killed in Cairo, while another five died in clashes south of the capital. It was Egypt's bloodiest day since security forces raided two pro-Morsi protest camps, killing hundreds.

Egyptian authorities had tightened security in anticipation of altercations with opponents of the current government who have repeatedly demonstrated for the reinstatement of President Mohammed Morsi since his ouster in early July.

Prior to the violence, Egypt's interior ministry had warned citizens against "attempts that may disturb the October 6 celebrations," the state news agency MENA reported early Sunday.

On Friday, supporters and opponents of the ousted Egyptian president clashed in Cairo, leaving four people dead and another 40 wounded.

kms, ccp/rc (AP, AFP, Reuters)