Four people died on Sunday as millions gathered in Egypt on the anniversary of President Mohammed’s Morsi inauguration.

Kol Yisrael radio reported that 17 million people hit the streets.

Three people died in Assiut, the report said, and a fourth in Bani Seuf, south of Cairo, Al Jazeera reported that the Cairo headquarters of Morsi’s Muslim Brotherhood was attacked by protesters with petrol bombs.

Tensions remained high and anti-Morsi crowds swelled as protests moved into the night hours. Morsi supporters held their own rallies in Nasr City and near the presidential palace.

Protesters directed their anger not just at Morsi but the ruling Muslim Brotherhood, which in two years has gone from a banned movement to the rulers.

“Mosques should be for religion, not for politics,” Ahmed Sultan, a student, told Al Jazeera.

The U.S. government was also the target of anger, with one banner reading: “America supports killers of the Egyptian people.”

The anti-Morsi protests have been organized by a grassroots campaign calling itself Tamarod, meaning “rebellion” or “insubordination”, which claims to have collected the signatures of 22 million Egyptians demanding the president leaves office.

The petition has no legal standing, but it has nonetheless tapped into widespread public anger towards Morsi. The president has made a number of controversial decisions since taking office, most notably a November decree which shielded his decisions from judicial review.

On Friday, Thousands of Egyptians gathered in Cairo in two opposing mass rallies, one calling for Morsi’s ouster, and another showing support for the embattled Islamist president.

Protests also took place in Alexandria, where American student Andrew Pochter of Chevy Chase, Maryland, was killed after being stabbed by a protester. Another man, an Egyptian, was also killed.