Shelling and missile strikes rocked the length of the Gaza Strip overnight into Tuesday, after Israel's army warned its war against the territory's Hamas rulers will last through 2024.

Nearly three months of conflict have claimed almost 22,000 lives in Gaza, according to the Hamas-run health ministry, and devastated much of the besieged territory.

Despite relentless global demands for a ceasefire, military spokesman Daniel Hagari said Monday the army was preparing for "prolonged fighting" expected to last "throughout this year".

Deep under the Red Sea, a passing Israeli warship could barely be heard as Yamit Avital held her breath and dived, her mind briefly cleared of the trauma of the October 7 Hamas attacks.

"There's a kind of tranquility to the sea, in the deep," Avital said after she emerged from 20 metres (66 feet) under the aquamarine waters of the Gulf of Aqaba, also known in Israel as the Gulf of Eilat.

"It's like you don't hear anything, you only hear the music of the sea."

Syrian dissident Riad Turk, who has been compared to Nelson Mandela for spending years in prison for his staunch opposition to the government, died Monday in exile in France, his daughter said.

"My father died peacefully and satisfied of what he has accomplished, surrounded by his two daughters and his grandchildren," Khuzama Turk told AFP. He was 93.

France's ambassador to Syria Brigitte Curmi wrote on X: "The Syrian Mandela Riad Turk just left us after a whole life of struggle for a free and democratic Syria.

Two weeks ahead of Palestine's opening game at the 2023 Asian Cup in Qatar, the team is struggling to focus as war rages on in Gaza, where thousands have been killed.

Some players have lost loved ones in Israel's relentless bombardment of the besieged territory in response to Hamas's October 7 attack on southern Israel.

Much of Gaza has been reduced to rubble, including stadiums, in air and artillery strikes and a ground offensive, and football fields have been used as makeshift graves for some of the dead as many cemeteries are either full or inaccessible.

Israel's war in Gaza will continue throughout 2024, a military spokesman said, insisting that the country was preparing for "prolonged fighting" against Hamas militants.

"The IDF (Israeli army) must plan ahead, understanding that we will be required for additional tasks and warfare throughout this year," Daniel Hagari told reporters late on Sunday.

"The objectives of the war require prolonged fighting and we are preparing accordingly."

Tens of thousands marched in Istanbul Monday to protest "murderer" Israel's war in Gaza and the killing of Turkish soldiers by outlawed Kurdish militants in Iraq.

The rally, called by a foundation which counts Bilal Erdogan, the son of President Recep Tayyip Erdogan, among its members started after crowds performed morning prayers at Istanbul's iconic mosques, including Hagia Sophia and the Blue Mosque.

Unrelenting Israeli bombardment rocked Gaza on Monday, while an army spokesman warned the war on the besieged territory's Hamas rulers will continue throughout 2024.

Israel's Defence Minister Yoav Gallant met troops inside Gaza on Monday, and vowed in a statement that "life will return to its course" for residents of border communities hit in Hamas's October 7 attacks that triggered the war.

Seconds after ringing in the new year on a lively street in Tel Aviv, some young Israelis found themselves running for cover while others kept the party going with a shrug as missile defence systems intercepted a barrage of rockets overhead.

The attack at the stroke of midnight, just as many were trying to forget about the war in the Gaza Strip, seemed to underscore the fatigue at the ongoing fighting expressed by many of the young revellers gathered to celebrate New Year's Eve.

The PGA Tour worked Sunday to extend a deadline into 2024 for finalizing a merger agreement with Saudi Arabian investors, tour commissioner Jay Monahan calling talks "active and productive."

The update to players in a memo from Monahan came hours ahead of the year-end deadline to approve a framework agreement merging the PGA Tour, DP World Tour and Saudi Public Investment Fund (PIF) that finances the upstart LIV Golf League.

More than 4,360 people, including combatants and civilians, were killed in Syria’s civil war in 2023, in the thirteenth year since fighting began, a war monitor said on Sunday.

The figure was an increase on 2022, when 3,825 people were killed.

That was the lowest annual death toll since the conflict began in 2011 with the government's brutal crackdown on peaceful pro-democracy protests, said the Syrian Observatory for Human Rights.