Lebanon's Hezbollah said it was moving to a new and escalating phase in its war against Israel while Iran said "the spirit of resistance will be strengthened" after the killing of Hamas leader Yahya Sinwar.
Sinwar, a mastermind of the October 7 attack that triggered the latest Gaza war, was killed during an exchange of fire with Israeli forces in the Palestinian enclave on Wednesday, a pivotal event in the year-long conflict.
Western leaders said his death offered an opportunity for the conflict to end, but Israeli Prime Minister Benjamin Netanyahu said the war would go on until the hostages seized by Hamas militants were returned.
"Today we have settled the score. Today evil has been dealt a blow but our task has still not been completed," Netanyahu said in a recorded video statement after the death was confirmed on Thursday.
"To the dear hostage families, I say: This is an important moment in the war. We will continue full force until all your loved ones, our loved ones, are home."
Sinwar, who was named as Hamas' overall leader following the assassination of political chief Ismail Haniyeh in Tehran in July, was believed to have been hiding in the warren of tunnels Hamas has built under Gaza over the past two decades.
He was killed during a gun battle in southern Gaza on Wednesday by Israeli troops who were initially unaware that they had caught their country's number one enemy, Israeli officials said.
The military released drone video of what it said was Sinwar, sitting on an armchair and covered in dust inside a destroyed building.
Hamas has not made any comment itself, but sources within the group have said the indications they have seen suggest Sinwar was indeed killed by Israeli troops.
Sinwar's death could dial up hostilities in the Middle East where the prospect of an even wider conflict has grown.

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