Top Iraqi Shia cleric warns of Middle East escalation amid Gaza war, Haniyeh and Shukr killings

Iraq's top Shia Muslim cleric Grand Ayatollah Ali Sistani warned on Saturday of the risk of a regional escalation with potentially "catastrophic consequences" following the killing of two Iran-backed militant leaders.

Sistani also urged an end to the "genocidal war" in Gaza, where the civil defence agency said an Israeli air strike Saturday on a school housing displaced Palestinians killed more than 100 people.

"Once again, the Israeli occupation army has committed a huge massacre, adding to its series of ongoing crimes" in Gaza, Sistani said in a rare statement since the start of the 10-month-old war, which has devastated the territory.

The recent high-profile killings of two leaders of Hamas and Hezbollah increased the danger of "major clashes" that could have "catastrophic consequences" for the region, he warned.

"We once again call on the world to stand against this terrible brutality," Sistani said, urging Muslims "to unite in order to press for an end to the genocidal war" in Gaza.

On July 31, Hamas's political leader Ismail Haniyeh was assassinated in an attack, blamed on Israel, in the Iranian capital Tehran.

It came hours after Israel killed Hezbollah senior military commander Fuad Shukr in a strike on a southern Beirut neighborhood which also killed several civilians, including two young children.

The assassinations, which prompted vows of retaliation by Iran and Hezbollah, are among the most serious in a series of tit-for-tat attacks that has heightened fears of a regional conflagration stemming from the Gaza war.

Most of Gaza's 2.4 million people have been uprooted by the war, and have been subject to a looming famine, high levels of food insecurity and the spread of disease - exacerbating the humanitarian situation in the territory. At least 39,790 Palestinians have been killed since October 7.