BEIRUT, May 20, 2024 (BSS/AFP) - Iran-backed members of the "Axis of Resistance" against Israel and its allies expressed their condolences Monday after Tehran confirmed President Ebrahim Raisi had died in a helicopter crash.

Palestinian militant group Hamas, Lebanon's Hezbollah movement, Yemen's Huthi rebels, the Syrian government and Iraq-based armed groups all mourned the death of Raisi and eight others on Sunday.

Also among those killed when the helicopter crashed into a remote mountainside in heavy fog was Iranian Foreign Minister Hossein Amir-Abdollahian, known for his fierce anti-Israel sentiment and scepticism of the West.

Hamas mourned Raisi as an "honourable supporter" of the Gaza-based group whose October 7 attack on Israel sparked the bloodiest ever war in the coastal territory.

Hamas said it appreciated Raisi's "support for the Palestinian resistance and tireless efforts in solidarity" with Palestinians since the start of the Israel-Hamas war in Gaza.

Iran has hailed the October 7 attack that triggered the war as a "success" but denied any involvement.

Hamas also praised Raisi and Amir-Abdollahian's "intense political and diplomatic efforts to stop the Zionist (Israeli) aggression against our Palestinian people".

Lebanon's powerful Hezbollah group, which has traded deadly cross-border fire with Israel amid the war, praised Raisi as "a strong supporter, and a staunch defender of our causes... and a protector of the resistance movements".

"Hezbollah in Lebanon extends its deepest condolences," the group said in a statement, adding that it had known Raisi "closely for a long time".

Mohammed Abdulsalam, a spokesperson for Yemen's Huthi rebels, said on X that Raisi's death was a loss "for the entire Islamic world and Palestine and Gaza".

Palestinians were "in dire need of the presence of such a president who continued to defend" their right to freedom, said the group, which has launched attacks against targets with alleged Israeli links in support of Palestinians.

Syrian President Bashar al-Assad expressed solidarity with close ally Tehran, which has backed him during more than a decade of civil war.

Assad "affirmed Syria's solidarity with the Islamic Republic of Iran and with the families of the late deceased and his comrades," the Syrian presidency said in a statement.

"We worked with the late President to ensure that strategic relations between Syria and Iran flourish always," the statement added.

Syria and Lebanon announced three official days of mourning.

Iraq's Popular Mobilisation Forces, or Hashed al-Shaabi, also expressed their sympathies, adding that Raisi had "always declared that Iraq and Iran are one people that cannot be separated".

The Hashed are an integral part of the official Iraqi security apparatus under the authority of the prime minister that also includes several pro-Iran armed factions.

Iraqi Prime Minister Mohamed Shia al-Sudani said that "we stand in solidarity with the Iranian people".