Cairo. At least 15 people have been killed and 83 injured in Egypt in clashes between police and supporters of the deposed Islamist President, Mohammed Morsi.
More than 200 members of the Muslim Brotherhood were reportedly arrested in connection with the violence in Cairo.
Supporters of Mr Morsi marched in several cities, as the military-backed government feted the 40th anniversary of the 1973 Arab-Israeli war.
Earlier, a Muslim Brotherhood supporter was killed in clashes with police.
At least two other people were injured in the fighting in the town of Delga about 300km (190 miles) south of Cairo, according to reports quoting a medical official and witnesses.
Security forces used tear gas and fired in to the air to stop thousands of supporters of Mr Morsi from entering Cairo’s Tahrir Square.
The street battles raged for hours with small fires burning and black smoke rising in several parts of the capital, according to reports.
Hundreds of people had gathered in Tahrir Square to mark the military anniversary. Jets and Apache helicopters flew overhead in formation, as part of a grand display of military hardware by the government.
Backers of Mr Morsi said they would use the public holiday commemorations to denounce what they say was as a military coup in July.
The BBC’s Quentin Sommerville in Cairo says night has fallen and there is the risk of more violence in Cairo. Meanwhile, the celebrations are continuing in Tahrir.
He earlier described people running for cover as gunshots and tear gas were fired in to the crowd. Egyptian society remains polarised by the military overthrow of Islamist president Mohammed Morsi in July.
The interior ministry earlier warned it would confront any “attempts that may disturb the 6 October celebrations”, the Mena state news agency reported.
In a televised address, Prime Minister Hazem Beblawi described it as a “critical time” for the country and urged Egyptians to “stand together, be optimistic about the future”.
Hundreds of Islamist protesters have died in violence since the Egyptian military deposed Mr Morsi in July, 13 months after he was elected as president.
He and other senior Brotherhood figures have been imprisoned and face trial.
The authorities are moving to seize the movement’s assets after its activities were banned as part of a crackdown.
However, Brotherhood supporters have continued to take to the streets to protest - albeit in smaller numbers than before.