Israel said it had scaled up a ground offensive in northern Gaza as part of an operation to extend so-called "security zones" that provide a protective buffer along the border with Israel.

Authorities in Hamas-ruled Gaza accuse Israeli forces of a "heinous massacre" with a strike on a school they say killed almost 30 people, many of them children.

At least 27 Palestinians have been killed in an Israeli air strike on a school in northern Gaza that was serving as a shelter for displaced families, the Hamas-run health ministry says.Dozens more were wounded when the Dar al-Arqam school in the north-eastern Tuffah district of Gaza City was hit,

The Israeli military said it was looking into reports about the deaths at a school-turned-shelter, which came as Israel was intensifying its offensive in Gaza to pressure Hamas to release hostages.

Hundreds of thousands of Gazans sought shelter as Israeli forces advanced into the ruins of the city of Rafah.

DEIR AL BALAH, Gaza Strip (AP) — An Israeli airstrike on Thursday killed at least 27 Palestinians sheltering at a school in northern Gaza and wounded 70 more, said Health Ministry spokesman Zaher al-Wahidi, as Israeli forces have expanded their strikes and evacuation orders across the war-torn territory in recent days.

Demanding an end to the war, hundreds pressed the militants to relinquish control of the enclave, a rare demonstration against a group that has suppressed dissent with violence.