GAZA/ISRAEL-GAZA BORDER/DOHA: Israeli tanks stormed back into parts of the northern Gaza Strip they had left last week, residents said on Tuesday, reigniting some of the most intense combat since the New Year when Israel announced it was scaling back its operations there.

Massive explosions could be seen over northern areas of Gaza from across the border with Israel - a rarity over the past two weeks after Israel announced a drawdown of forces in the north as part of a transition to smaller, targeted operations.

The rattle of gunfire reverberated across the border through the night. In the morning, contrails snaked through the sky as Israel's Iron Dome defences shot down rockets fired by Hamas across the fence - proof they retain the capability to launch them despite more than 100 days of war.

Israel said its forces had killed dozens of Hamas fighters overnight in clashes in Beit Lahiya on Gaza's northern fringe. Gaza health authorities said the last 24 hours of Israeli bombing had killed 158 people in the Palestinian enclave, raising their toll for the war, now in its fourth month, to 24,285, with thousands more bodies feared lost in the rubble.

Israel launched the war to eradicate Hamas after they stormed across the border fence on Oct. 7, killing 1,200 people and capturing 240 hostages, according to Israeli tallies.

The White House said on Tuesday that U.S. Middle East envoy Brett McGurk had been in Qatar in recent days "for very serious and intensive discussions" about a possible deal to release more hostages held by Hamas in Gaza.

"We are hopeful it will bear fruit and bear fruit soon," White House national security spokesperson John Kirby told reporters. U.S. and Qatari mediation brought about the release of over 100 hostages during a brief truce in late November.

HUMANITARIAN CRISIS

The war has driven most of Gaza's 2.3 million people from their homes, some of them several times, and caused a humanitarian crisis, with food, fuel and medical supplies running low.

In a move to help ease the suffering, Qatar announced that it and France had brokered a deal between Israel and Hamas for medication and humanitarian aid to be delivered to civilians in Gaza in exchange for medication for Israeli captives in Gaza.

Under U.S. pressure to reduce civilian casualties, Israel had said it was transitioning from a full-scale ground assault to targeted operations against the Hamas that control the enclave.

It began that shift with a pullback in the north. Defence Minister Yoav Gallant also said on Monday that the more recent ground assault in the south was drawing to a close.

But de-escalating the war still seems an uphill challenge, with Israel saying it will not rest until Hamas is wiped out and showing no sign of losing the means to resist.

Israel Ziv, a retired general who formerly commanded Israeli forces in Gaza, told Reuters that 10-15% of Hamas' pre-war rocketry corps of some 1,000 personnel were believed to be still alive, with some 2,000 rockets left to be fired.

The war has also inflamed tensions across the region, including in the Red Sea, where the Iran-aligned Houthi movement that controls most of Yemen has been attacking commercial ships. The route is used by 15% of world shipping. The group says it is targeting vessels linked to Israel in solidarity with Gaza.

The U.S. and Britain have responded by bombing Houthi targets in Yemen to prevent what they called a threat to global commerce. The U.S. military on Tuesday carried out a new strike against four Houthi anti-ship ballistic missiles as they were being readied for more attacks, two U.S. officials told Reuters.

'FORGIVE ME, MY SON. I COULD NOT PROTECT YOU'

Some of the hundreds of thousands of residents who fled northern Gaza earlier in the war had begun returning last week to areas where the Israelis had withdrawn. But residents who spoke to Reuters on Tuesday said the abrupt resurgence of fighting in the north would now halt plans to try to go home.

"We almost planned to return to our house in Nazla, east of Jabalia, but thank God we didn't. This morning people living nearby arrived here and told us the tanks pushed back there," said Abu Khaled, 43, a father of three now living with relatives in severely damaged Gaza City.

Israeli forces have fought their way to the centre of Gaza's main southern city of Khan Younis, and into towns north and east of the central city of Deir al-Balah.

In Khan Younis, Zaher Abu Zarifa wept and cradled a black plastic body bag holding his seven-year-old son Saif, one of at least 11 bodies brought out at a hospital morgue.

The boy was killed by a missile while playing on a bicycle by a school gate, his father said.

Later, by a small freshly dug grave, a gravedigger unzipped the bag so the father could kiss the boy's face, then zipped it back up, took the boy and gently laid him in the ground.

"Forgive me, my son. I could not protect you," the father repeated. "Forgive me, my son. I could not protect you."