Protesters opposing Egyptian President Mohamed Mursi gather during a demonstration at Tahrir Square in Cairo June 30, 2013. Egyptians poured onto the streets on Sunday, swelling crowds that opposition leaders hope will number into the millions by evening and persuade Islamist President Mohamed Mursi to resign. [Photo/Agencies]

CAIRO - At least four people were killed in Egypt and nearly 200 wounded on Sunday in clashes between supporters and opponents of Islamist President Mohamed Mursi, security and medical sources said.

All four dead were shot in Nile Valley towns south of Cairo, one in Beni Suef and three in Assiut. Across the country, the Health Ministry said, 174 people were given medical treatment as a result of factional fighting in the streets.

In Cairo and Alexandria, more than one million demonstrated.

Hundreds of people throwing petrol bombs and rocks attacked the national headquarters of Mursi's Muslim Brotherhood. The building caught fire as guards and protesters exchanged gunfire.