This photo released by the Israel Defense Forces (IDF) on Jan 23, 2024 shows Israeli troops conducting military operations in the southern Gaza Strip. (PHOTO / IDP VIA XINHUA)

JERUSALEM - The Israel Defense Forces (IDF) said Tuesday that its troops have surrounded the main southern Gaza Strip city of Khan Younis after its 24 soldiers were killed in Gaza in the worst single-day toll on Monday.

At a press briefing, IDF Spokesman Daniel Hagari said 21 soldiers were killed in an explosion in central Gaza on Monday. They were preparing explosives to demolish two buildings when coming under a rocket-propelled grenade attack by the Palestinian militants, which triggered a premature explosion and resulted in the collapse of the buildings, with the soldiers either inside or nearby.

While we bow our heads in memory of our fallen, we are not relenting, even for a moment, in striving for the goal that has no alternative -- achieving total victory. 

Benjamin Netanyahu, Israeli Prime Minister

In a statement, the army said the fatalities were reserve soldiers aged 22 to 37, adding three others were killed elsewhere also on Monday.

READ MORE: 21 Israeli troops dead in Gaza attack as fighting rages

On the army's worst one-day loss, Israeli Prime Minister Benjamin Netanyahu said, "While we bow our heads in memory of our fallen, we are not relenting, even for a moment, in striving for the goal that has no alternative -- achieving total victory."

TV broadcasts on Israeli channels showed funerals, with coffins draped in the national flag, taking place across the country.

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Hundreds of the slain soldiers' relatives and friends attended the ceremonies, mourning and consoling each other in grief.

IDF Chief of the General Staff Herzi Halevi made a televised statement after visiting the location of the explosion. "On this day, we feel the great and painful cost of war," he said.

This photo released by the Israel Defense Forces (IDF) on Jan 23, 2024 shows Israeli troops conducting military operations in the southern Gaza Strip. (PHOTO / IDP VIA XINHUA)

Halevi added that the troops fell during a mission to demolish buildings and vegetation, aiming to create a new "buffer zone" between the enclave and Israel that would "enable the safe return of the residents of southern Israel to their homes."

At least 25,490 Palestinians have been killed by the Israeli strikes on the enclave, according to the Gaza-based Health Ministry on Tuesday

Meanwhile, Israeli forces announced Tuesday morning in a statement that they "encircled" Khan Younis, and updated in a press statement on the evening that they had killed more than 100 Hamas militants in the west Khan Younis over the day.

According to Israel's Ha'aretz newspaper, the troops besieged hospitals in the city and blocked evacuation routes to Gaza's southernmost Rafah city, where more than 50 percent of Gaza's 2.3 million population sought shelter from the relentless Israeli bombardments.

READ MORE: At least 30 killed in Israeli bombing on southern Gaza

At least 25,490 Palestinians have been killed by the Israeli strikes on the enclave, according to the Gaza-based Health Ministry on Tuesday.

Israel's state-owned Kan TV news reported that Hamas has rejected an Israeli proposal on a new deal that offered a two-month ceasefire and the release of Palestinian prisoners in exchange for the release of all hostages held in Gaza and that Hamas leadership leaves Gaza.