Police and protesters demanding that Egypt's ruling military council step down are observing a truce after five days of deadly street battles in which at least 40 people died.
Egypt's military also issued a statement apologising for the loss of life and vowing to bring to justice those responsible for the deaths of protesters in Cairo's iconic Tahrir Square and elsewhere in the country.
Army troops have used metal bars and barbed wire to build barricades to separate protesters and police on side streets leading from Tahrir to the nearby interior ministry. Most of the fighting has been taking place on those side streets.
The truce came into effect after international criticism of Egypt's military rulers mounted, and a rights group raised the death toll for the wave of violence to at least 38.
The United Nations strongly condemned what it called an excessive use of force. Germany, one of Egypt's top trading partners, called for a quick transfer of power to a civilian government. The United States and the UN secretary general expressed their concern over the use of violence against mostly peaceful protesters.
Navi Pillay, the UN High Commissioner for Human Rights, deplored the role of Egypt's security forces in attempting to suppress protesters.
"Some of the images coming out of Tahrir, including the brutal beating of already subdued protesters, are deeply shocking, as are the reports of unarmed protesters being shot in the head," she said.
"There should be a prompt, impartial and independent investigation, and accountability for those found responsible for the abuses that have taken place should be ensured."
She said the actions of the military and police were enflaming the situation, prompting more people to join the protests.
"The more they see fellow protesters being carted away in ambulances, the more determined and energised they become."