Compounding Morsi's woes, four of his advisers resigned Wednesday, joining two other members of his 17-member advisory panel who have abandoned him since the crisis began.
Six tanks and two armored vehicles belonging to the Republican Guard, an elite unit tasked with protecting the president and his palaces, were stationed Thursday morning at roads leading to the palace in the upscale Cairo district of Heliopolis. The guard's commander, Maj. Gen. Mohammed Zaki, sought to assure Egyptians that his forces were not taking sides.
"They will not be a tool to crush protesters and no force will be used against Egyptians," he said in comments carried by the official MENA news agency.
The situation was calm Thursday morning, with thousands of Morsi supporters camping outside the palace after driving away opposition activists who had been staging a sit-in there, prompting fierce street battles that spread to residential areas.
"I don't want Morsi to back down," said Khaled Omar, a Brotherhood supporter. "We are not defending him, we are defending Islam, which is what people want."
Other Brotherhood supporters outside the palace accused opposition protesters of being Mubarak loyalists or foot soldiers in a coup attempt.
"They want to take over power in a coup. They are conspiring against Morsi and we want him to crack down on them," said one, Ezzedin Khoudir. "There must be arrests."
The violence began when the Brotherhood called on its members to head to the presidential palace to "defend legitimacy" and protect it against what a statement termed attempts by the opposition to impose its will by force. In response, thousands descended on the area, chasing away some 300 opposition protesters who had been staging a peaceful sit-in outside the palace's main gate. Clashes later ensued with the two sides using rocks, sticks and firebombs.