Lebanon’s Hezbollah fired a massive barrage of rockets into northern Israel on Wednesday to avenge the killing of a top commander, further escalating regional tensions as the fate of an internationally-backed plan for a ceasefire in Gaza hung in the balance.

The retaliatory attack came as US secretary of state Antony Blinken was in the region to push a cease-fire proposal with global support that has not been fully embraced by Israel or Hamas. The militant group submitted its first official response late Tuesday, requesting “amendments” to the deal.

Hezbollah, an Iran-backed ally of Hamas, has traded fire with Israel nearly every day since the eight-month-long Israel-Hamas war began and says it will only stop if there is a truce in Gaza.

Air raid sirens sounded across northern Israel, and the military said that about 160 projectiles were fired from southern Lebanon, making it one of the largest attacks since the fighting began. There were no immediate reports of casualties as some were intercepted while others ignited brush fires.

Hezbollah said it fired missiles and rockets at two military bases in retaliation for the killing of Taleb Sami Abdullah, 55. Known within Hezbollah as Hajj Abu Taleb, he is the most senior commander killed since the fighting began eight months ago. The Israeli strike destroyed a house where Abdullah and three other officials were meeting, about 10 km from the border, late on Tuesday.

A Hezbollah official told The Associated Press that Abdullah was in charge of a large part of the Lebanon-Israel front, including the area facing the Israeli town of Kiryat Shmona, which Hezbollah has repeatedly attacked in recent days, causing fires in the area.

The official, who spoke on condition of anonymity, said Abdullah had joined Hezbollah decades ago and took part in attacks against Israeli forces during their 18-year occupation of southern Lebanon.

Israeli airstrikes have killed over 400 people.