GAZA CITY, Gaza Strip — Israel escalated its military campaign against Hamas on Tuesday, striking symbols of the militant group’s control in Gaza and firing tank shells that Palestinian officials said shut down the strip’s only power plant in the heaviest bombardment in the war so far.

Hours after the power plant was hit, thick black smoke still rose from the plant’s burning fuel tank. The station’s shutdown was bound to lead to further serious disruptions of the flow of electricity and water to the 1.7 million people packed into the narrow Palestinian territory.

The heavy strikes were a new blow to international efforts to reach a sustainable truce in the fighting, now in its fourth week.

At least 100 Palestinians were killed Tuesday, including 36 who died in airstrikes and tank shelling on five homes, according to Palestinian health officials and the Palestinian Red Crescent. In one strike Tuesday afternoon, 10 members of one family were killed and 50 people were wounded in tank shelling in the northern Gaza town of Jebaliya, the officials said.

That pushed the overall death toll since the conflict began on July 8 to at least 1,156, according to Gaza Health Ministry spokesman Ashraf al-Kidra.

Israel has reported 53 soldiers and three civilians killed.

In the West Bank, a top PLO official offered a 24-hour truce Tuesday, saying he also spoke in the name of Hamas, but the Islamic militants said they want to hear from Israel first. Israeli government spokesman Mark Regev declined comment.

Israeli Prime Minister Benjamin Netanyahu on Monday warned of a “prolonged” campaign against Hamas.

But it was not clear if Netanyahu has decided to expand the Gaza war into an all-out effort to topple Hamas or planned to limit Israel’s operation to the previously stated goal of ending Hamas rocket fire and destroying Hamas’s sophisticated network of cross-border tunnels.

Already, the intensity and the scope of the current Gaza operation is on par with an invasion five years ago, which ended with a unilateral Israeli withdrawal after hitting Hamas hard.

On Tuesday, Israeli warplanes carried out dozens of attacks, leveling the home of the top Hamas leader in Gaza, Ismail Haniyeh, and damaging the offices of the movement’s Al-Aqsa satellite TV station, a central mosque in Gaza City and government offices.

Israel has targeted several homes of Hamas leaders but none has been killed – presumably because they have kept a low profile.

Even before the power plant shutdown, Gaza residents only had electricity for about three hours a day because fighting had damaged power lines. This means most of Gaza will now be without power.