BEIRUT (AP) U.S. Secretary of State Antony Blinken said Wednesday that mediators would keep trying to close an elusive cease-fire deal after Hamas proposed numerous changes to a U.S.-backed plan, some of which he said were workable and some not.

The back-and-forth laid bare frustration over the difficulty of reaching an accord that can bring an end to eight months of war that has decimated Gaza, killed tens of thousands of Palestinians and left scores of Israeli hostages still languishing in militant captivity. Previous moments of optimism have been repeatedly dashed by the differences between the two sides.

The cease-fire proposal has global support but has not been fully embraced by Israel or Hamas. Blinken did not spell out what changes Hamas was seeking but he said the mediators Qatar, Egypt and the U.S. will keep trying to close this deal. He put the onus on Hamas, accusing it of changing its demands.

Hamas has proposed numerous changes to the proposal that was on the table. ... Some of the changes are workable. Some are not, Blinken told reporters in Qatar. I believe that they (the differences) are bridgeable, but that doesnt mean they will be bridged because ultimately Hamas has to decide.

Blinkens comments came as Lebanons Hezbollah fired a massive barrage of rockets into northern Israel to avenge the killing of a top commander, further escalating regional tensions.

Hezbollah, an Iran-backed ally of Hamas, has traded fire with Israel nearly every day since the 8-month-long Israel-Hamas war began and says it will only stop if there is a truce in Gaza. That has raised fears of an even more devastating regional conflagration.

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.

Hamas asks for changes