Khamenei said Israel was acting like a “rabid dog” and “a wild wolf”.
Israel stepped up its bombardment of the Gaza Strip warning people in three densely populated areas to vacate their homes.
Seven children killed when the Israeli missile hit the playground, a Palestinian official said.
“Unfortunately the world doesn’t blame the Israelis,” said Meshaal.
“How should a mother feel when she opens her eyes on the day of Eid and does not see her son next to her?” said Abir Shammaly.
Indian-origin Israeli soldier Refael Degorker was laid to rest on Sunday in a military cemetery in his hometown.
At least two Palestinians were killed in fresh airstrikes by Israel despite calls for immediate ceasefire.
Hamas said it would be willing to abide by a new 24-hour humanitarian truce ahead of the Eid al-Fitr holiday.
Gaza crisis enters its 19- day conflict; close to 1000 Palestinians and 39 Israelis have been killed in the crossfire.
Earlier this week, 10 Gaza militants dressed in Israeli army uniforms popped out of the ground.
718 Palestinians, mainly civilians, have been killed, while 32 Israeli soliders have lost their lives since the conflict began.
Ban demanded that militants groups, who are responsible should be held accountable for endangering the lives of civilians.
U.S. Secretary of State John Kerry reported some progress in ceasefire talks.
Calls for ‘immediate ceasefire’ and ‘peaceful dialogue’
Several international airlines halted flights to Israel indefinitely, citing security concerns.