GAZA/CAIRO — At least 70 Palestinians were killed and dozens wounded in Israeli airstrikes across Gaza on Thursday, after Israel resumed its bombing campaign on the enclave, a Gaza health official said.

Medics said Israeli strikes targeted several houses in northern and southern areas of the Gaza Strip. There was no immediate comment from Israel.

On Wednesday, the Israeli military said its forces had resumed ground operations in central and southern Gaza, after a cease-fire that had broadly held since January collapsed.

The renewed ground operations came a day after the Israeli air force killed more than 400 Palestinians in one of the deadliest episodes since the beginning of the conflict in October 2023.

Since Tuesday, airstrikes have killed 510 Palestinians, with more than half of them women and children, the health official told Reuters.

The Israeli military said its operations extended Israel's control over the Netzarim Corridor, which bisects Gaza, and were a "focused" manoeuvre aimed at creating a partial buffer zone between the north and the south of the enclave.

Hamas said the ground operation and the incursion into the Netzarim Corridor were a "new and dangerous violation" of the two-month-old cease-fire agreement. In a statement, the group reaffirmed its commitment to the deal and called on mediators to "assume their responsibilities."

Speaking to Reuters on Thursday, a Hamas official said mediators had stepped up their efforts with the two warring sides but added that "no breakthrough has yet been made."

The group has made no clear threats to retaliate.

Gaza's health authorities announced that more than 49,000 Palestinians have been killed since Oct. 7, 2023, when Hamas launched its al-Aqsa Flood operation against southern Israel, during which it took around 250 people hostage back to Gaza. Fifty-two hostages remain in the Strip, with about 24 believed to still be alive.

Reporting by Nidal al Mughrabi in Cairo; Editing by Kim Coghill and Sharon Singleton