A senior adviser to Iran's supreme leader Ayatollah Ali Khamenei expressed support for an attack Hamas launched against Israel on Saturday, calling it a "proud operation".
"We support the proud operation of Al-Aqsa Flood," Yahya Rahim Safavi said at a meeting held in support of Palestinian children in Tehran, quoted by ISNA news agency.
"We support this operation, and we are sure that the resistance front also supports this issue," said Safavi, who is senior general in the Islamic Revolutionary Guard Corps.
The Palestinian group Hamas, which governs the besieged Gaza Strip, launched numerous rockets at Israel from dawn on Saturday with many of its militants crossing into Israel.
At least 100 people have been killed in Israel, according to the Israeli Army Radio, with hundreds more injured.
The death toll is the blockaded Gaza Strip stands at least 198 so far, according to the Palestinian Ministry of Health, with over 1,610 injured.
Israel has attacked the besieged Gaza Strip numerous times over recent years. In May this year, at least 34 Palestinians were killed by Israeli rocket fire.
Safavi expressed backing for the Palestinian groups "until the liberation of Palestine and Jerusalem".
Meanwhile, Iran's foreign ministry spokesman Nasser Kanani also hailed the Palestinian assault on Israel.
"Today's operation marked a new page in the field of resistance and armed operations against the occupiers," he said.
"The resistance has so far achieved brilliant victories during this operation, and this is a bright spot in the history of the Palestinian people's struggle against the Zionists."
At a parliament session on Saturday, Iranian lawmakers chanted "Down with Israel", "Down with America", and "Welcome Palestine", according to a video published by Tasnim news agency.
Iran, which hosted leaders of Hamas and Islamic Jihad in June, considers Israel its arch enemy.
The two sides have for years been engaged in a shadow war, with Iran accusing Israel of a series of sabotage attacks and assassinations targeting its nuclear programme.
Meanwhile, allies Israel and the United States have previously accused Iran of using drones and missiles to attack US forces and Israel-linked ships in the Gulf.