16 people have been killed and 781 wounded in violence across Egypt since Sunday, according to the health ministry.
Nine of the deaths took place in Cairo and seven in the governorates of Alexandria, Beni Suef, Kafr El-Sheikh, Fayoum and Assiut.
Eight of the nine Cairo deaths happened as violence flared outside the Muslim Brotherhood headquarters in the suburb of Moqattam, when those inside fired at youth hurling petrol bombs and stones at the building.
The four-storey headquarters was overrun and ransacked by dozens of youths on Monday morning following a night of deadly violence which the Islamist group blamed on "thugs."
Also in Cairo, 23-year-old man died "from pneumonia and shortness of breath" outside the Ittihadiya presidential palace, a focal point of Sunday's million-strong rallies against Islamist President Mohamed Morsi.
Millions of Egyptians took to the streets across the country on Sunday to call for Morsi to step down, while tens of thousands of the president's mostly Islamist backers have been camped out for the fourth consecutive day outside a local mosque in Cairo in support of his electoral mandate.
Factional rivalries have triggered street fighting across Egypt over the past week, with mounting fears of further violence over the coming days of demonstrations.
On Sunday, three protesters were shot dead in Upper Egypt’s Assiut in clashes between supporters and opponents of the beleaguered president.
One protester was killed in similar deadly clashes in Egypt's second city of Alexandria, one in the Nile Delta's Kafr El-Sheikh, one in Beni Suef and one in Fayoum.
In Alexandria, a woman died on Monday after succumbing to injuries sustained on Friday. She had been accidentally shot by a birdshot pellet while standing on her balcony watching clashes between rival demonstrations in the Mediterranean city.