CAIRO - Security forces and armed men clashed with supporters of Egypt's ousted president early Saturday, killing at least 65 protesters in mayhem that underscored an increasingly heavy hand against protests demanding Mohammed Morsi's return to office.
In chaotic scenes, pools of blood stained the floor and bodies were lined up under white sheets in a makeshift hospital near the site of the battles in eastern Cairo. Doctors struggled to cope with the flood of dozens of wounded, many with gunshots to the head or chest.
It was the deadliest single outbreak of violence since the military ousted Morsi on July 3 and one of the deadliest in more than two years of turmoil in Egypt.
The extent of the bloodshed pointed to a rapidly building confrontation between the country's two camps, sharply divided over the coup that removed Egypt's first freely elected president after widespread protests against his rule.
Authorities talk more boldly of making a move to end weeks of protests by Morsi's largely Islamist supporters. At the same time, the Islamists are growing more assertive in challenging security forces as they try to win public backing for their cause.
Saturday's clashes were sparked when pro-Morsi protesters sought to expand their main Cairo sit-in camp by moving onto a nearby main boulevard, only to be confronted by police and armed civilians - reportedly residents of nearby neighborhoods. Police initially fired tear gas, but in ensuing clashes the protesters came under gunfire.
Officials from Morsi's Muslim Brotherhood and their allies decried what they called a new "massacre" against their side, only weeks after July 8 clashes with army troops in Cairo that left more than 50 Morsi supporters dead.
U.S. Secretary of State John Kerry said that he spoke to Egyptian authorities, saying it is "essential" they respect the right to peaceful protest. He called on all sides to enter a "meaningful political dialogue" to "help their country take a step back from the brink."
But neither side has shown much taste for reconciliation. Islamists staunchly reject the new leadership and insist the only possible solution to the crisis is to put Morsi back in office. Meanwhile, the interim leadership is pushing ahead with a fast-track transition plan to return to a democratically elected government by early next year.
And the military-backed authorities appear confident of public support for a tougher hand after millions turned out for nationwide rallies Friday called by army chief Gen. Abdel-Fattah el-Sissi as a mandate against "terrorism and violence."
Interior Minister Mohammed Ibrahim, who is in charge of police, took an uncompromising stance in a press conference after the violence. He accused the pro-Morsi side of provoking bloodshed to win sympathy.
"We didn't go to them: They came to us - so they could use what happened for political gain," he said. Ironically, Ibrahim is originally a Morsi appointee, and his then-boss praised him for a tough hand after police killed dozens of anti-Morsi protesters in the city of Port Said earlier this year.
"The Ministry of Interior never has and never will fire on any Egyptian," he added, saying police only fired tear gas in Saturday's violence.