Palestinian health officials said at least 13 people, including women and children, were killed in two Israeli strikes on two houses in Nuseirat, one of the enclave’s eight historic refugee camps.
There has been no immediate comment by the Israeli army on the two strikes.
Another strike on a school sheltering displaced Palestinian families in the Tuffah neighborhood of Gaza City killed at least seven people, medics added.
It accused Hamas of using the civilian population and facilities for military purposes, which Hamas denies.
Later on Tuesday, two separate Israeli attacks killed five Palestinians in Rafah in the southern Gaza Strip and the Zeitoun suburb of Gaza City, medics said.
In Khan Younis, in the south of the enclave, six Palestinians were killed in an Israeli air strike on a tent housing displaced people, medics said.
Hours later, an Israeli airstrike on a car in western Khan Younis, killed six Palestinians, medics said. Footage circulated on social media, which Reuters could not immediately authenticate, showed a mangled, burnt-out vehicle.
The renewed surge in violence in Gaza comes as Israel began a ground operation in Lebanon, saying its paratroopers and commandos were engaged in intense fighting with Iran-backed Hezbollah. The conflict follows devastating Israeli airstrikes against Hezbollah’s leadership.
Hezbollah began firing rockets into Israel almost a year ago, in support of its ally Hamas in the war in Gaza, which began on Oct. 7.
The assault, in which Israel says 1,200 people were killed and more than 250 taken hostage, triggered the war that has devastated Gaza, displacing most of its 2.3 million population and killing more than 41,600 people, according to Gaza health authorities.
Some Palestinians said they feared that Israel’s shift in focus to Lebanon could prolong the conflict in Gaza, which marks its first anniversary next week.
The eyes of the world now are on Lebanon while the occupation continues its killing in Gaza. We are afraid the war is going to go on for more months at least,” said Samir Mohammed, 46, a father of five from Gaza City.
“It is all unclear now as Israel unleashes its force undeterred in Gaza, Yemen, Syria, Lebanon, and God knows where else in the future,” he told Reuters via a chat app.