Some regional leaders urged restraint after Saturday's deadly Hamas attack targeting Israel and the retaliation that followed, but others blamed Israel itself and some celebrated the surprise assault.
The early morning Hamas offensive by air, land and sea was met by Israeli air strikes on the blockaded coastal enclave, in the bloodiest escalation with the Palestinians since May 2021.
"We are at war," Israeli Prime Minister Benjamin Netanyahu said, promising that "the enemy will pay an unprecedented price".
In Iran, a senior adviser to supreme leader Ayatollah Ali Khamenei expressed support for the attack, calling it a "proud operation".
"We support this operation," Yahya Rahim Safavi said, quoted by ISNA news agency. Safavi backed the Palestinian militants "until the liberation of Palestine and Jerusalem".
In parliament, lawmakers chanted "Down with Israel", "Down with America" and "Welcome Palestine", according to a video published by the Tasnim news agency.
Lebanon's powerful Iran-backed Hezbollah praised Hamas for what it called its "heroic operation".
Elsewhere, Egyptian President Abdel Fattah al-Sisi warned "against the danger of the situation deteriorating and sliding into more violence". In a call with French President Emmanuel Macron, he urged international cooperation on stopping the conflict from getting worse.
Cairo has historically been a key mediator in conflicts between the two sides.
Jordan's Foreign Minister Ayman Safadi warned of the "volatility" of the situation, "particularly in light of what cities and areas of the West Bank are witnessing of Israeli attacks and violations against the Palestinian people".
Jordan and Egypt were the first two countries in the region to agree peace deals with Israel.
Arab League chief Ahmed Aboul Gheit urged "an immediate halt to military operations in Gaza" and "the cycle of armed confrontation between the two sides".
He said: "Israel's continued implementation of violent and extremist policies is a time bomb depriving the region of any serious opportunity for stability in the foreseeable future." (AFP)