Pope Francis suggested Sunday that Israel's attacks in Gaza and Lebanon have been “immoral” and disproportionate, saying its military domination has gone beyond the rules of war.

Francis was asked en route home from Belgium about Israel's targeted killing of one of Hezbollah's founding members, Hassan Nasrallah. Friday's strike in Beirut targeted an area greater than a city block and reduced several residential buildings to rubble, and at least six other deaths have been confirmed.

Francis didn't mention Israel by name and said he was speaking in general terms. But he said that “the defense must always be proportionate to the attack.”

“When there is something disproportionate, there is a dominating tendency that goes beyond morality,” he said. “A country that does these things — and I'm talking about any country — in a superlative way, these are immoral actions.”

He said that even if war itself is immoral, there are rules that “indicate some morality.”

“But when you don't do this … you see the bad blood of these things,” he said.

The death of Nasrallah has sent shockwaves throughout Lebanon and the Middle East, where he has been a dominant political and military figure for more than three decades.

US President Joe Biden said the Israeli strike was a “measure of justice” for victims of Hezbollah's “reign of terror”.

Francis has tried to strike a balance in his comments on the Oct 7 Hamas attack on Israel and the conflicts in Gaza and southern Lebanon that have ensued. He has called for an immediate cease-fire, for the release of hostages taken by Hamas and for humanitarian aid to get to Gaza.

Francis repeated that he calls the Catholic parish in Gaza every day to see how they are doing