Israeli troops have encircled the city of Khan Younis in southern Gaza, the IDF said today in a statement, a day after it deepened its campaign in the area with an intense new assault that Palestinian officials said left many civilians who had fled there in danger.

"Over the past day, IDF troops carried out an extensive operation during which they encircled Khan Yunis and deepened the operation in the area. The area is a significant stronghold of Hamas’ Khan Yunis Brigade," the IDF said in a statement.

"IDF ground troops engaged in close-quarters combat, directed IAF strikes, and used intelligence to coordinate fire, resulting in the elimination of dozens of terrorists," it added.

The IDF also said it found weaponry and military compounds in the area.

NBC News has not verified the claims.

TEL AVIV — Current and former Israeli officials said they were stunned when news began to spread of the deadliest day for Israeli soldiers since the start of the war with Hamas.

Israeli Prime Minister Benjamin Netanyahu said that it was “one of the most difficult days since the outbreak of the war,” in a post on X.

“I would like to stand by the dear families of our heroic fighters who fell on the battlefield,” Netanyahu said in the post. “I know that for these families, their lives will change forever.”

The news of the incident stunned Israelis, many of whose attention has been focused on intense fighting around Khan Younis, where Israeli forces have closed in. Some in the intelligence community believe Hamas leader Yahya Sinwar may be hiding in tunnels beneath the southern city in the Gaza Strip.

The Palestinian Red Crescent has said hundreds of Gazans have been killed in recent days in Khan Younis and said civilians there don’t have the aid they need.

An image released by the Israeli Army yesterday shows IDF soldiers aiming weapons during ground operations in the Gaza strip.

TEL AVIV — Israeli leaders marked an “unbearably difficult” morning after 21 soldiers were killed yesterday in Gaza.

“On behalf of the entire nation, I console the families and pray for the healing of the wounded,” Israeli President Isaac Herzog said in a post on X. He said the soldiers had fallen in a “war that has every justification.”

Israeli Defense Minister Yoav Gallant said it was a “hard and painful morning,” adding “our hearts are with our precious families during their hardest hour.”

“This war will determine the fate of Israel in the next decades — our fallen soldiers are an imperative to achieve war objectives,” he said.

TEL AVIV — The Israeli military has said that 21 soldiers were killed in an incident in Gaza yesterday, thought to be the deadliest single attack for the country's troops since the war began.

The reservists were operating in what IDF spokesman Daniel Hagari called the “buffer zone” between Israeli communities and the Palestinian enclave when the incident occurred. He said forces were demolishing buildings and infrastructure in the area, around 600 meters from the border, as part of an effort to secure the area so residents of southern Israel could eventually return back home.

The soldiers had been preparing two two-story buildings with explosives to be demolished, Hagari said this morning. At around 4 p.m. local time, an RPG missile was fired at a tank that was helping to protect the soldiers, he said. At the same time, an explosion occurred in the buildings, causing them to collapse on top of the soldiers.

Hagari said the IDF was still investigating the exact circumstances of the incident.

A picture taken from Rafah shows smoke billowing over the city of Khan Younis in the southern Gaza Strip yesterday.

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