The Egyptian army is bracing itself for a showdown as the internal turmoil in the country shows no signs of ending with supporters of the new administration run by the armed forces and deposed president Mohamed Morsi's Muslim Brotherhood planning mass rallies.
General Abdel Fatah al-Sisi, the army chief who is virtually running the new government, has called for a show of support on the streets; and the Muslim Brotherhood has countered by planning 35 marches across the capital Cairo, raising the prospect of clashes.
''We will not initiate any move, but will definitely react harshly against any calls for violence or black terrorism from Brotherhood leaders or their supporters,'' Reuters quoted an army officer as saying.
Another military officer said the army had given Morsi's Muslim Brotherhood a Saturday deadline to end its resistance and join a road-map to fresh elections.
Over 200 Egyptians have already died in clashes between Morsi's supporters, opponents and security forces since protests against the ex-president began in late June.
Meanwhile, an investigating judge today ordered the detention of Morsi for allegedly colluding with the Palestinian Islamist group Hamas during the 2011 uprising that toppled former dictator Hosni Mubarak.
Morsi's detention has been extended by 15 days for investigation into the charges. He is likely to be transferred to the same Cairo prison where former leader Hosni Mubarak is now held, Egypt's new interior minister Mohamed Ibrahim said today.
Ibrahim also said pro-Mursi sit-ins would "God willing, soon ... be dealt with" based on a decision by the prosecutor, who has been examining legal complaints by citizens about the protests that have blocked major Cairo thoroughfares.
"God willing, it will be broken up in a way that does not cause losses," he said referring to sit-ins that have lasted about a month. "But, God permitting, it must end. We hope that they come to their senses ... and join their political process."
The minister accused the pro-Mursi camp of exaggerating the numbers killed in clashes. He said security forces used teargas to disperse demonstrators on a bridge because of concerns they could cause the bridge to collapse by lighting vehicle tyres.
The minister also said a decision on where to hold Mursi, whose current location has not been announced, would be up to the investigating judge. When pressed by journalists about where Mursi would be taken, he said "mostly likely to Torah" prison.
Torah, on the edge of Cairo, is the jail where Mubarak, his sons and members of the former president's cabinet have been held after they were detained in the wake of the uprising that erupted in January 2011.