Egyptian protesters carry away a man suffering from tear gas during clashes with riot police near Tahrir Square in Cairo.
Egypt's military rulers apologized on Thursday for the deaths of demonstrators at the hands of police as protests demanding an immediate handover to civilian control entered a seventh day.
At least 35 protesters have been killed since Saturday -- when clashes erupted -- and more than 2,000 injured, prompting expressions of concern from Western governments and a call from the United Nations for an independent inquiry into the "excessive use of force."
Demonstrators again camped out overnight in Tahrir Square, the iconic heart of the 18 days of protests that ousted veteran president Hosni Mubarak in February, to demand that the military leadership step down immediately.
The mass protests, which placatory moves by the military have failed to dampen, threaten to eclipse the first post-Mubarak parliamentary elections due to begin on Monday.
"The Supreme Council of the Armed Forces presents its regrets and deep apologies for the deaths of martyrs from among Egypt's loyal sons during the recent events in Tahrir Square," it said in a statement on its Facebook page.
"The council also offers its condolences to the families of the martyrs across Egypt."
The statement came after a speech by SCAF chairman Field Marshal Hussein Tantawi on Tuesday which was aimed at placating protesters in the square but was heavily criticised for not making mention of the deaths at the hands of police.
The SCAF vowed to investigate and prosecute all those behind the deaths.
It also pledged to offer assistance to the families of the dead and injured, and to set up a military field hospital in Tahrir Square.
Activists said sporadic clashes continued into the night on Mohammed Mahmud, a flashpoint street connecting the heavily-fortified interior ministry to the square, where dozens of tents have been pitched.
Egyptian-American columnist Mona al-Tahawy was arrested overnight after joining the protests for democratic change. Her last post on Twitter said she was "beaten arrested in interior ministry."
"The square boils," read the front-page headline of the state-owned Al-Akhbar newspaper, while Al-Ahram lamented the "renewed bloodshed."
The protest deaths prompted an unusually strongly worded statement from Al-Azhar, Sunni Islam's highest seat of learning, calling on police not to shoot at demonstrators.
Grand imam Sheikh Ahmed al-Tayyeb said that any dialogue "stained with blood is doomed and its fruit will be bitter."
Al-Azhar "calls on the police leadership to immediately issue orders not to point their weapons at demonstrators... no matter what the reasons," Tayyeb said in a recorded address broadcast on state television.
It calls "on the armed forces to throw all their weight behind preventing confrontations between one people," he added.
Three people died in clashes with police in and around Tahrir on Wednesday, a medic said.
A fourth was shot dead in the northwestern city of Mersa Matruh when security forces clashed with demonstrators trying to storm a police station, state media said.
Clashes were also reported in the Mediterranean city of Alexandria, where hundreds of people protested outside the military headquarters, calling for the immediate transfer of power to a civilian administration.
UN High Commissioner for Human Rights Navi Pillay called the images coming out of Egypt "deeply shocking," and urged the authorities to end their "clearly excessive use of force" against protesters.
British Foreign Secretary William Hague expressed deep concern at the "unacceptable violence and loss of life" in and around Tahrir.
Egypt's military ruler pledged in a rare televised address on Tuesday night to hold a presidential election by the end of June -- six months earlier than scheduled.
Tantawi said he was also ready to transfer power immediately, through a referendum, "should the people wish it."
But tens of thousands of protesters in Tahrir railed against Tantawi, who served as defence minister for two decades under Mubarak before taking the reins when he stepped down.
An opinion poll published by the University of Maryland on Wednesday found that 43 percent of respondents believed Egypt's military rulers were working to slow or reverse the transition to democracy.
Analysts said that while the demonstrators in Tahrir Square might not represent the majority of the Egyptian population, their influence was unquestionable.
"We are seeing middle class youth being killed, and that moves big segments in the cities and provinces," said Nabil Abdel Fatah of the Al-Ahram Centre for Political and Strategic Studies.