CAIRO — Security forces fired tear gas and clashed Monday with several thousand protesters in Cairo's Tahrir Square in the third straight day of violence that has killed at least 22 people and has turned into the most sustained challenge yet to the rule of Egypt's military.
Throughout the day, young activists demanding the military hand over power to a civilian government skirmished with black-clad police, hurling stones and firebombs and throwing back the tear gas canisters being fired by police in to the square, which was the epicenter of the protest movement that ousted President Hosni Mubarak.
The night before saw an escalation of the fighting as police launched a heavy assault that tried and failed to clear protesters from the square. In a show of the ferocity of the assault, the death toll quadrupled from Sunday evening until Monday morning. During the overnight clashes, police hit a makeshift field clinic operated by protesters in the square, forcing them to evacuate bloodied wounded to a nearby mosque.
The eruption of violence, which began Saturday, reflects the frustration and confusion that has mired Egypt's revolution since Mubarak fell in February and the military stepped into power.
It comes only a week before Egypt is to begin the first post-Mubarak parliamentary elections, which many have hoped would be a significant landmark in a transition to democracy. Instead, it has been clouded by anger at the military's top body, the Supreme Council of the Armed Forces, which will continue to rule as head of state even after the vote. Activists accuse the generals of acting increasingly in the same autocratic way as Mubarak's regime and seeking to cling to power.
The military says it will only hand over power after presidential elections, which it has vaguely said will be held in late 2012 or early 2013. The protesters are demanding an immediate move to civilian rule.
The Health Ministry said Monday that at least 22 people have been killed since the violence began Saturday — a jump from the toll of five dead around nightfall Sunday.
The violence looks set to intensify with some of the protesters on Monday lobbing firebombs at the police.
"We must use force against force. We cannot just throw stones at them," said Hassan Mohammed, a protester in his 20s.
"Do you expect us to meet blood with kindness?" asked a bearded teenager climbing a tree with a firebomb in hand. "We will burn it under their feet," he added as he went on to use expletive against the Supreme Council's head, Field Marshal Hussein Tantawi.
Doctors at field hospitals set up in the square spoke of scores of protesters arriving with breathing and eye problems and wounds to the face from what they said was the excessive use of tear gas and rubber bullets.
Mohammed Mustafa, one of the doctors, said his field hospital was treating an average of 80 cases per hour and that many of the wounded did not want to be taken to hospital in ambulances because they feared arrest.
The protesters' suspicions about the military were fed by a proposal issued by the military-appointed Cabinet last week that would shield the armed forces from any civilian oversight and give the generals veto power over legislation dealing with military affairs.
But other concerns are also feeding the tensions on the street. Many Egyptians are anxious about what the impending elections will bring. Specifically they worry that stalwarts of Mubarak's ruling party could win a significant number of seats in the next parliament because the military did not ban them from running for public office as requested by activists.
The military's failure to issue such a ban has fed widely held suspicion that the generals are reluctant to dismantle the old regime, partly out of loyalty to Mubarak, their longtime mentor.
The Supreme Council of the Armed Forces issued a statement, read on state TV Sunday night, saying it does not intend to "extend the transitional period and will not permit by any means hindering the process of democratic transition."
The military-backed Cabinet said the elections due to start on Nov. 28 will go ahead as scheduled.
Activists have been holding occasional protests against the military in Tahrir for months, and some have seen crackdowns by the military or police.
But this weekend's violence was the most sustained fighting between the two sides. It began when security forces stormed a sit-in at Tahrir staged by several hundred protesters wounded in clashes during the 18-day uprising in January and February and frustrated by the slow pace of bringing those responsible to justice.