U.N. rights chief Navi Pillay called Friday for a probe into the reported mass execution by rebels of Syrian soldiers taken captive in fighting in the north of the country this week.

Pillay said the events during fighting for control of the town of Khan al-Assal in the northern province of Aleppo were "deeply shocking".

U.S. Middle East envoy William Burns will arrive in Cairo on Friday night, a senior Egyptian official said, as international efforts to resolve Egypt's political crisis ramp up.

"Burns is arriving tonight. He will meet with foreign minister Nabil Fahmy tomorrow," the source told Agence France Presse.

Yemeni presidential guards clashed with hundreds of soldiers protesting in front of the president's palace in Sanaa on Friday, leaving one dead and six wounded, a military official and witnesses said.

A gunfight broke out as angry soldiers, who had gathered at nearby Sabiin Square to demand compensation, tried to march on the palace, the witnesses told Agence France Presse.

Islamist backers of Egypt's deposed President Mohammed Morsi staged defiant rallies on Friday, as police prepared to disperse their Cairo protest camps amid international appeals to avoid further bloodshed.

The new demonstrations came after U.S. Secretary of State John Kerry said Egypt's military had been "restoring democracy" when it deposed Morsi, in comments that prompted fury from the ousted leader's supporters.

The worst violence to hit Iraq in five years is a major challenge, Prime Minister Nuri al-Maliki said in remarks broadcast on Friday, as attacks killed eight people.

July was the deadliest month for Iraq since 2008, when the country was emerging from a bloody sectarian conflict, Iraqi government and United Nations figures released on Thursday showed.

Fresh clashes between Kurdish fighters and jihadists erupted in the majority Kurdish province of Hasakeh in northern Syria early on Friday, a monitoring group said.

At least 12 members of the Islamic State of Iraq and the Levant (ISIS) were killed, said the Syrian Observatory for Human Rights, which added that 22 Kurdish fighters have been killed over the past few days.

Iran held massive anti-Israel rallies Friday, with president-elect Hassan Rowhani calling the arch-foe Jewish state a "wound" on the Muslim world, drawing a sharp response from Israeli Prime Minister Benjamin Netanyahu.

"In our region, a wound has for many years been sitting on the body of the Islamic world in the shadow of occupation of the holy land of Palestine and the dear Quds (Jerusalem)," Rowhani said in remarks broadcast on state television.

Iran's outgoing President Mahmoud Ahmadinejad warned arch-foe Israel Friday in one of his last public speeches that a regional storm was brewing that would "uproot" the Jewish state.

"I will inform you with God as my witness, a devastating storm is on the way that will uproot the basis of Zionism," Ahmadinejad said in Quds (Jerusalem) Day remarks broadcast on state television.

Jordanian border guards have foiled an attempt to smuggle large amounts of weapons and drugs into the kingdom from Syria, the army said Friday.

"Forces of the frontier guard yesterday evening (Thursday) seized large quantities of munitions and different types of drugs during an attempt to smuggle them into the kingdom," the army said in a statement.

Tunisian forces launched a land and air operation against Islamist militants near the Algerian border on Friday, the military said, as Tunis battles a crisis sparked by a political slaying.

"A huge operation, with ground and air units, was launched at dawn to clean up the (Chaambi) mountain" area, armed forces spokesman Taoufik Rahmouni told Tunisian media.