Human Rights Watch on Tuesday demanded a probe of Egypt’s President Abdel Fattah al-Sisi and two other officials for "crimes against humanity" in a crackdown that killed hundreds of protesters.

Human Rights Watch on Tuesday demanded a probe of Egypt's President Abdel Fattah al-Sisi and two other officials for "crimes against humanity" in a crackdown that killed hundreds of protesters.

Security forces stormed two sit-ins of supporters of ousted president Mohammad Mursi in Cairo's Rabaa al-Adawiya and Nahda squares on August 14, 2013, resulting in what HRW termed "one of the largest killings of demonstrators in a single day in recent history".

A HRW report said its own investigation into the crackdown and interviews with more than 200 witnesses showed that security forces intentionally used "excessive lethal force" in breaking the sit-ins.

"The killings not only constituted serious violations of international human rights, but likely amounted to crimes against humanity," according to the report, which HRW released to mark one year since the carnage.

HRW said its report identifies the most senior security officials and key leaders in the chain of command "who should be investigated .. including Interior Minister Mohammad Ibrahim, then defense minister Abdel Fattah al-Sisi, and Medhat Menshawy," who led the crackdown at Rabaa al-Adawiya.

In a conference call, HRW executive director Kenneth Roth said the evidence gathered showed that the crackdown was a planned operation "that senior commanders ordered or quickly should have stopped but didn't.

"This was not a war... most of the day police operated openly, shooting at people," he said.

"These were widespread systematic attacks on civilian population," Roth said.
"We are saying that the evidence is sufficient that those three people in particular warrant investigation into their role," said HRW activist Omar Shakir.

In the lead up to the crackdown, officials had "envisioned killing of several thousand protesters," he said.

At least 817 demonstrators died in Rabaa al-Adawiya square alone on that day, HRW said.