By George Wright, BBC News
People inspect the damage following Israeli bombardment in Rafah on the southern Gaza Strip on 29 December 2023. Photo: AFP
The Israeli military has said it expects the conflict in Gaza to continue throughout 2024.
In a New Year's message, the Israel Defense Forces (IDF) spokesman said troop deployments were being adjusted to prepare for "prolonged fighting".
Daniel Hagari said some troops - especially reservists - would be withdrawn to allow them to regroup.
"These adaptations are intended to ensure the planning and preparation for continuing the war in 2024," he said.
"The IDF must plan ahead out of an understanding that there will be additional missions and the fighting will continue the rest of the year."
He said that some reservists would leave Gaza "as soon as this week" to allow them to "re-energise ahead of the coming operations".
A Palestinian holds the body of a relative killed in Israeli strike at the Nasser hospital in Khan Yunis on the southern Gaza Strip on 28 December 2023. Photo: AFP
Some 21,978 people - mostly women and children - have been killed in Gaza since 7 October, according to the Hamas-run health ministry. Its latest update said 56,697 people in Gaza had been wounded over the same period.
The figures included 156 people killed and 246 injured in the last 24 hours, the ministry added.
The latest war was triggered by an unprecedented cross-border attack by Hamas gunmen on southern Israel on 7 October, in which 1200 people were killed - most of them civilians - and about 240 others taken hostage.
Israel continued its bombardment of Gaza up until the end of what has been a dark year in the region.
The IDF said it killed a senior Hamas commander involved in the 7 October attack, Adil Mismah, in an overnight strike on the town of Deir al-Balah.
The Gaza health ministry reported at least 48 deaths in overnight bombing in Gaza City. Witnesses told the AFP news agency that another strike killed 20 people sheltering at Al-Aqsa University in the city's west.
Another strike on Monday morning was said to have killed at least 10 people in the Al-Maghazi refugee camp.
The BBC has not been able to verify the latest battlefield reports.
A resident of northern Gaza displaced to the south of the enclave highlighted the contrast between New Year celebrations around the world and the situation in Gaza.
"Tonight the sky in world countries will be lit by firecrackers, and joyful laughs will fill the air," Zainab Khalil, 57, told Reuters on Sunday.
"In Gaza our skies are now filled with Israeli missiles and tank shells that land on innocent, homeless civilians."
Palestinians waiting to collect food at a donation point in Deir El-Balah, in the central Gaza Strip, on 24 December 2023. Photo: Majdi Fathi / NurPhoto / NurPhoto via AFP
The UN says 85 percent of Gaza's 2.4 million people - almost 2 million - have now been displaced.
Thousands of doses of vaccines against childhood diseases, including polio and measles, have been delivered to Gaza, to help tackle a growing health emergency, Reuters reports.
The news agency quoted the Palestinian health ministry as saying that supplies estimated to cover vaccinations for up to 14 months had entered through the Rafah border crossing with Egypt.
Speaking from Rafah, Ayadil Saparbekov from the World Health Organization told the BBC that vaccines were crucial because of the conditions in which Gazans were living.
"Thousands of people live together in overcrowded camps with very poor water conditions, poor hygiene and very poor sanitation - these are all breeding grounds for various diseases," he said.
Israeli Prime Minister Benjamin Netanyahu said on Saturday that "the war is at its height".
"We are fighting on all of the fronts," he said. "We have huge success but we also have painful cases. Achieving victory will require time.
"As the [army] chief of staff has said, the war will continue for many more months."
Far-right Israeli Finance Minister Bezalel Smotrich walks with soldiers during a visit to Kibbutz Kfar Aza near the border with the Gaza Strip on 14 November 2023. Photo: Gil Choen-Magen / AFP
Israel's far-right Finance Minister Bezalel Smotrich called for Palestinians to leave Gaza and make way for Israelis who could "make the desert bloom".
The official line from the Israeli government is that Gazans will eventually be able to return to their homes, though it has yet to outline how or when this will be possible.
Air raid sirens sounded in Tel Aviv and southern Israel as it saw in the new year, with Israeli missile defence systems intercepting rockets fired from Gaza, AFP reported.
One man who was in Tel Aviv celebrating the new year with friends said: "I was terrified, like it was the first time I saw missiles. It's terrifying."
Hamas's military wing, the Ezzedine al-Qassam Brigades, said in a video posted on social media that it carried out both attacks.
They said M90 rockets were used in "response to the massacres of civilians" perpetrated by Israel.
- This story was first published by BBC.