Iran's President Ebrahim Raisi spoke Sunday with leaders of Palestinian militant groups Hamas and Islamic Jihad, official media said, a day after Hamas launched a surprise attack on Israel.
"Raisi discussed the developments in Palestine in separate phone calls with Ziyad al-Nakhalah, secretary general of the Islamic Jihad Movement, and Ismail Haniyeh, the head of the (Hamas) political bureau," state news agency IRNA reported, without giving further details.
Militants from Hamas, which controls the Gaza strip, penetrated Israel at dawn on Saturday under cover of a massive rocket barrage.
Israel's government said the worst fighting in decades has killed more than 600 Israelis and that Hamas took more than 100 people hostage. On the Gaza side at least 313 were reported dead.
Iran hailed the Palestinian attack calling it a "proud operation" and a "great victory".
"This victorious operation, which will facilitate and accelerate the collapse of the Zionist regime, promises the impending destruction of the Zionist regime," said Ali Akbar Velayati, a senior adviser to Iran's supreme leader Ayatollah Ali Khamenei.
"I am congratulating this great and strategic victory, which is a serious warning to all compromisers in the region," he added in a letter to Hamas and Islamic Jihad on Saturday.
The Islamic republic hosted talks with leaders of Hamas and Islamic Jihad in June.
At the time, Raisi said that Israel was seeking to normalise ties with more Arab and Muslim countries "to discourage young Palestinians from (seeking to) liberate the occupied territories", according to the Iranian presidency.
On Saturday, hundreds gathered in major cities in Iran, including in Tehran's Palestine Square, carrying the Palestinian flag and pictures of slain General Qasem Soleimani, who was assassinated in a US drone attack in Baghdad in 2020 after overseeing the Revolutionary Guards' foreign operations for more than a decade.
Large billboards celebrating the "Al-Aqsa Flood" operation were installed in Tehran including one that says "the great liberation operation has begun".
Crowds in some cities set off fireworks and torched Israeli flags while others carrying the Palestinian colours took to the streets while motorists honked their honks in jubilation, according to footage carried by the official IRNA news agency.
Iran does not recognise Israel and has made support for the Palestinian cause a centrepiece of its foreign policy ever since the Islamic Revolution of 1979.
The two governments have engaged in a shadow war for years, with Iran accusing Israel of a series of sabotage attacks and assassinations targeting its nuclear programme.
The United States and Israel have previously accused Iran of using drones and missiles to attack US forces and Israel-linked ships in the Gulf.