Supporters of deposed Islamist president Mohamed Morsi, who was overthrown in a July military coup, tried to converge on a central Cairo square for the anniversary celebrations, when police confronted them. At least 30 people were killed in Cairo, and four south of the capital, and 209 people were wounded, senior health ministry official Khaled al-Khatib said in a statement.
An interior ministry official said no policemen were killed in the clashes. In central Cairo, policemen fired shots and tear gas to disperse stone-throwing protesters. According to reports several suspected demonstrators were being arrested and beaten.
Three months after Morsi's overthrow, followed by a harsh crackdown on his Muslim Brotherhood movement, the Islamists had planned to galvanise their protest movement in a symbolic attempt to reach Tahrir Square.Sunday 's death toll was the highest in clashes between Islamists and police since several days of violence starting on August 14 that killed more than 1,000 people, mostly Islamists.
After several weeks of relative calm, the Islamists said they would escalate their protests by trying to rally in the symbolic Tahrir Square.
Islamists and police clashed on the anniversary of the 1973 Arab-Israeli war.
Hundreds of thousands of people had filled the square in February 2011 to force president Hosni Mubarak to resign, and again in July 2013 to urge the army to depose his successor Morsi. But on Sunday, security forces guarded entrances to the square, frisking people arriving for the anniversary celebrations.
Several thousand people, some carrying pictures of army chief Abdel Fattah al-Sisi, waved Egyptian flags as warplanes flew overhead in formation and patriotic songs blared from loudspeakers.
Elsewhere in the city, the air was thick with tear gas and the crackle of gunfire as police confronted several marches heading for Tahrir. In Delga, an Islamist bastion south of Cairo, one person was killed when Islamists clashed with civilian opponents and police, a health ministry official and witnesses said.