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Israel's military said on Saturday it has expanded operations, with infantry and armoured corps after entering northern Gaza overnight.
The army is “advancing in the stages of war” after “forces entered the northern area of the Gaza Strip and expanded the scope of ground operations” on Friday, military spokeswoman Ella Waweya told The National.
The military released grainy images of tank columns moving slowly in open areas of Gaza and said warplanes bombed dozens of Hamas tunnels and underground bunkers overnight.
“Infantry, armoured vehicles, engineering, and artillery forces are taking part in this operation, and it is accompanied by massive gunfire,” Capt Waweya said.
The Israeli military "in co-operation with the General Security Service [Shin Bet], last night eliminated other brigades commanders, including a commander in the Hamas air force and the commander of the naval force in the Gaza Brigade, who had planned and led an attempt to infiltrate Israeli territory via a beach of Zikim”, she said.
Military spokesman Daniel Hagari said ground forces were still "in the field" on Saturday, without elaborating.
Troops were being supported by fire from the air and sea, Rear Adm Hagari said.
He said Israel was "broadening the humanitarian effort" and would allow lorries carrying food, water and medicine to enter southern Gaza, addressing concerns about the plight of civilians in the Palestinian territory after three weeks of a total blockade and heavy bombardment that has claimed more than 7,000 lives.
On Friday, Israeli bombardment knocked out communications in Gaza, cutting off the 2.3 million people there from the outside world.
The blackout and the military's warning of intensified attacks increased speculation that Israel's long-expected invasion of Gaza was imminent.
Before internet and phone lines went down, foreign diplomats in Israel said they warned friends by messaging apps to stay indoors for the night, while messages from civilians and UN officials who work with Gazans flooded social media.
US officials painted a similar picture to ABC News on Friday evening.
The US and other allies have rallied around Israel since October 7, when Hamas militants stormed the fence separating Gaza from southern Israel and attacked communities nearby. More than 1,400 people were killed in the attacks and more than 200 taken hostage in the deadliest single-day assault the country has faced since it was founded in 1948.
Israel launched attacks on Gaza within hours, promising to destroy Hamas once and for all.
Israeli military experts who spoke to The National said that while securing the release of hostages was important, it was not the main priority – a major departure from earlier policy.
The experts said the focus had to be on totally destroying Hamas, or the militant group and its allies on Israel’s borders would adopt the same strategy again.
However, reports this week said the release of hostages was being pursued through Qatar, which has good connections with Hamas.
The US promised to do all it can to keep hostage talks going in the event of a ground invasion of Gaza.
There were also reports that Washington believes Israel is not prepared for a ground offensive, which would send its troops into one of the toughest environments for urban warfare.
Israel accuses Hamas of using civilian infrastructure in the densely populated territory to launch attacks, and its residents as human shields. The military claimed on Friday that Hamas’s main control centre was located under Gaza’s Al Shifa Hospital.