Dozens killed in Cairo crackdown on ousted leader's supporters Clashes erupted early Saturday in Cairo between security forces and supporters of Egypt's ousted President Mohammed Morsi, killing at least 38 protesters and overwhelming field hospitals with the wounded, a medic said, in an outburst of violence that deepens the battle lines in the country's political crisis. Other reports put the death toll at more than 100. Health Ministry spokesman Khaled el-Khateeb said that a government hospital near the clashes has received so far 21 dead, and 180 wounded. The difference could not be immediately reconciled. The violence overnight near the month-old sit-in held by Morsi's supporters is likely to harden the resolve of the deposed leader's camp, who described the latest bloodshed as a "massacre." On the other side of the political divide, the military-backed interim leadership appears to feel emboldened to move against Morsi's Muslim Brotherhood following mass rallies on Friday in support of a crackdown against the ousted president and his Islamist allies. The clashes began after hundreds of Morsi supporters moved out of their sit-in outside of the Rabaah al-Adawiyah Mosque in east Cairo late Friday. One group began to set up tents on an adjoining boulevard, where they planned to stay for at least three days, said Mahmoud Zaqzouq, a Brotherhood spokesman. At the same time, another group of protesters marched toward a nearby overpass, where they were met by volleys of tear gas from the police. The demonstrators responded by hurling rocks and stones at the security forces. The confrontation quickly turned bloody. At first, doctors said half a dozen were killed in the clashes, mostly by birdshots and some live ammunition. At the crack of dawn, the pace of casualties picked up and a nearby field hospital was unable to cope with the influx, according to Yehia Mikkia, a doctor at the makeshift facility. He said hundreds were wounded. Mikkia, the field hospital doctor, said 38 people had been killed, and that most of the casualties had wounds to the upper part of the body. He said the number of dead is likely to be higher because other casualties were transported to different hospitals. At the makeshift morgue at the sit-in, supporters chanted "The people want to execute the butcher," referring to army chief and Defence Minster Gen. Abdel-Fattah el-Sissi, as they ushered the dead out to the hospitals. In footage broadcast on Al-Jazeera Mubashir Misr TV, the bodies of more than 12 men shrouded in white cloth were laid out on the floor of the field hospital. Pools of blood colored the floor red. The state news agency MENA quoted an unnamed senior security official saying that the security forces had not used gunfire against the protesters, only tear gas. Early Saturday, he said security forces tried to prevent fighting between residents of the area and the protesters, and that eight members of the security forces were wounded, including some by birdshot. MENA said minor clashes continued into the morning. It said Morsi supporters pelted security forces with rocks and firebombs, while security closed off the road with barbed wire and responded with tear gas. The bloodshed is one of the deadliest bouts of violence in Egypt since the military deposed Morsi on July 3 after days of massive street protests calling for his ouster. It also comes almost three weeks after more than 50 people, mostly Brotherhood supporters, died in a similar outbreak of violence outside a military installation near the same sit-in. Since the military coup, Egypt's political standoff has deepened as both sides have dug in. Morsi's supporters reject the new political order, and say the military illegally ousted the country's first democratically elected leader. They have kept their sit-in and held near daily rallies elsewhere in the capital to demand Morsi be reinstated. While the main sit-in has been peaceful, protests elsewhere have turned violent at times, and some 180 people have been killed in clashes nationwide since June 30 when the demonstrations against Morsi began. The unrest, as well as claims that Islamist groups are stockpiling weapons and escalating attacks against troops in the Sinai, were used by the country's new military-backed rulers as a basis for demanding popular support. On Wednesday, el-Sissi called for mass rallies to give the military a mandate to fight "violence and terrorism," raising speculation that he may be planning a crackdown on the toppled president's allies. On Friday, massive crowds turned out to voice their support for a tough hand against Morsi's backers and the Muslim Brotherhood group from which he hails. The ousted president's supporters also held large rallies, although smaller than those of the pro-military camp. The rival demonstrations in Cairo were mostly peaceful into the evening, but clashes between supporters and opponents of Morsi left seven killed in the coastal city of Alexandria. As crowds gathered on Friday afternoon, authorities announced that Morsi was formally placed under investigation on a host of allegations including murder and conspiracy with the Palestinian militant group Hamas. Morsi has been held incommunicado since being taken into military custody on July 3. Interim President Adly Mansour told the private TV station al-Hayat that his government seeks to include everyone, but it will not accept lawlessness, blocked roads and attacks on state institutions. He urged the pro-Morsi protesters to go home, promising they won't be pursued or arrested. I can't negotiate with whoever has committed a crime. But those who were duped or those who want to belong to Egyptian society, we welcome them," he said. But he added: "The state must interfere (against lawlessness) firmly."