Israel vowed to eliminate new Hamas chief Yahya Sinwar, the alleged mastermind of the October 7 attack, with regional tensions threatening to boil over as the Gaza war entered its 11th month on Wednesday.

The naming of Sinwar to lead the Palestinian militant group came as Israel braced for potential Iranian retaliation over the killing of his predecessor Ismail Haniyeh last week in Tehran.

Speaking at a military base on Wednesday, Prime Minister Benjamin Netanyahu said Israel was “determined” to defend itself.

“We are prepared both defensively and offensively,” he told new recruits.

Army chief Lieutenant General Herzi Halevi vowed to “find him (Sinwar), attack him” and force Hamas to find another leader.

Sinwar — Hamas’s leader in Gaza since 2017 — has not been seen since the October 7 attack, the deadliest in Israel’s history.

A senior Hamas official told AFP the selection of Sinwar sent a message that the organisation “continues its path of resistance”.

Hamas’s Lebanese ally Hezbollah congratulated Sinwar and said the appointment affirms “the enemy… has failed to achieve its objectives” by killing Hamas leaders and officials.