Israeli forces kept up their assault on the Gaza Strip on Wednesday and told civilians to leave a refugee camp in the north of the Palestinian enclave after the war reached into Lebanon with the killing in Beirut of the Hamas deputy leader.

Israel has neither confirmed nor denied that it killed Saleh al-Arouri in a drone strike in the Lebanese capital on Tuesday. But military spokesperson Rear Admiral Daniel Hagari said Israeli forces were in a high state of readiness and prepared for any scenario.

The assassination was a further sign that the nearly three-month war between Israel and Hamas was spreading across the region, drawing in the occupied West Bank, Hezbollah forces on the Lebanon-Israel border, and even Red Sea shipping lanes.

Arouri, 57, who lived in Beirut, was the first senior Hamas political leader to be assassinated since Israel began its offensive against the militant group in response to its deadly rampage into Israeli towns on Oct. 7.

Hamas politburo member Hossam Badran said in a eulogy for Arouri: “We say to the criminal occupation (Israel) that the battle between us is open.”

Israel had long accused him of orchestrating attacks on its citizens. But a Hamas official said he was also “at the heart of negotiations” conducted by Qatar and Egypt over the outcome of the Gaza war and the release of Hamas-held Israeli hostages.

Hezbollah chief Sayyed Hassan Nasrallah was due to make a speech in Beirut later on Wednesday. Previously he had warned Israel against carrying out assassinations on Lebanese soil, vowing a “severe reaction”.