GAZA CITY, Gaza Strip — Israel unleashed its heaviest air and artillery assault of the 22-day Gaza conflict Tuesday, destroying key symbols of Hamas control, shutting down the territory's only power plant and leaving at least 128 Palestinians dead on the bloodiest day yet.
Despite devastating blows that left the packed territory's 1.7 million people cut off from power and water — and sent the overall death toll past 1,200 — Hamas' military leader remained defiant as he insisted that the Islamic militants would not cease fire until its demands are met. Hamas has demanded that Israel and Egypt lift a border blockade they imposed on Gaza after Hamas seized the territory in 2007.
The comments by Mohammed Deif in an audiotape broadcast on a Hamas satellite TV channel cast new doubt on international cease-fire efforts. Aides to Palestinian President Mahmoud Abbas said Egypt was trying to bring Israeli and Palestinian delegations together in Cairo for new talks.
Israel's final objective in Gaza remained unclear a day after Prime Minister Benjamin Netanyahu warned Israelis to be prepared for a prolonged war.
Netanyahu is under pressure from hawkish members of his coalition to topple Hamas in an all-out offensive but has not let on whether he plans to go beyond destroying Hamas rocket launchers, weapons depots and military tunnels used to infiltrate Israel and smuggle weapons.
The military said Palestinian militants fired at least 64 rockets Tuesday at Israeli cities.
Dozens of Israeli airstrikes and heavy tank shelling hit areas across Gaza, which was plunged into darkness Tuesday night after a strike on its sole power plant. The strikes also leveled the home of the top Hamas leader in Gaza and damaged government offices.
At least 1,229 Palestinians have died, including Tuesday's 128, making it the single deadliest day since the start of fighting on July 8, Palestinian health official Ashraf al-Kidra said.
Israel says it has lost 53 soldiers, along with two Israeli civilians and a Thai national.