CAIRO - Islamist supporters of Egypt's ousted president, Mohamed Morsi, will rally on Friday to express their outrage at his overthrow by the army and to reject a planned interim government backed by their liberal opponents.
Dozens of people were wounded in clashes in Morsi's home city on Thursday, raising fears of more of the violence in which several dozen have died in the past month. There were also militant attacks in the restive Sinai peninsula, next to Israel.
How the army deals with trouble will help determine future support for Cairo from the United States and other international powers. Concern that the generals have carried out a military coup against Egypt's first-ever freely elected leader has left Washington reviewing the $1.5 billion in military and civilian aid it annually gives Egypt.
The planned protests have the slogan "Friday of Rejection".
A military source said: "We will continue to secure the places of protest with troops, and jets if necessary, to make sure the pro- and anti-Morsi demonstrators don't confront each other. We will let them demonstrate and go where they want."
Morsi's political opponents insist there was no coup. Rather, the army heeded the "will of the people" in forcing the president out. Millions rallied on Sunday to protest at a collapsing economy and political deadlock, in which Morsi had failed to build a broad consensus after a year in office.
After a busy day of diplomacy by concerned Obama administration officials interrupting their Independence Day holiday in Washington, the Egyptian armed forces command issued a late-night statement guaranteeing rights to protest and free expression and pledging not to pursue arbitrary measures against any political group.
The uncontroversial phrasing belied a busy 24 hours since the military chief suspended the constitution, detained Morsi and oversaw the swearing in of the chief justice of the constitutional court as Egypt's interim head of state.
In addition to Morsi, the country's first freely elected leader, several senior figures in his Muslim Brotherhood were arrested, security sources said. Prosecutors were investigating various charges, including incitement to violence and, in the case of Morsi himself, insulting the judiciary.
Television channels owned by or seen as sympathetic to the Brotherhood were unceremoniously taken off air. The state printer did not run off its party newspaper on Thursday.
In Zagazig, the Nile Delta city where Mursi has a family home, 80 people were injured. Witnesses said the army moved in to seal the area after an attack on pro-Mursi protesters by men on motorcycles led to clashes with sticks, knives and bottles.
For a movement that has been banned and politically oppressed for most of its 85-year history, such developments have reinforced impressions among the Islamists that a "deep state", once loyal to fallen autocrat Hosni Mubarak and his army-backed predecessors, is still determined to crush it.
The armed forces' longtime US sponsor - which provides $1.3 billion in annual military aid - has voiced concern for human rights, but also for the stability of the biggest Arab nation. Egypt's peace with Israel and control of the Suez Canal give it a strategic importance for many beyond its 84 million people.
The White House has avoided condemning Morsi's ouster as a "coup", a distinction that could trigger legal US obstacles to aid. Some on Obama's national security team had contacted Egyptian officials "to convey the importance of a quick and responsible return of full authority to a democratically elected civilian government", it said.
In a statement on its Facebook page, the Egyptian military command said: "Wisdom, true nationalism and constructive human values that all religions have called for, require us now to avoid taking any exceptional or arbitrary measures against any faction or political current."
That appeared to be a response to concern internationally that, following Morsi's overthrow, there was a campaign of arrest and intimidation against the Brotherhood.
Egypt's caretaker Foreign Minister Mohamed Kamel Amr said that US Secretary of State John Kerry had expressed concern during a telephone call on Thursday for human rights:
"He was worried about the status of human rights," Amr said. "Understandably. I assured him there is no retribution, no acts of vengeance, that nobody will be treated outside the law."
Amr, a career diplomat who tended his resignation to Morsi after Sunday's anti-government protests, said he had spent the day calling international counterparts and briefing ambassadors with the message that there had been no "military coup" in Egypt. The army had merely heeded the popular will.
Of his conversation with Kerry, he said: "I told him that the main aim of the military now is to maintain security.
"There will be no acts of violence, no acts of exclusion. Everybody will be included. The idea is to have everybody participating in the transitional process."