The bodies of four Israeli hostages recovered last week were found in a tunnel in Jabaliya in northern Gaza, the Israel Defense Forces said Monday.

The bodies of Shani Louk, Amit Buskila, Ron Benjamin and Yitzchak Gelernter -- who were killed during the Oct. 7 Hamas attack and taken into Gaza -- were recovered following a monthslong operation, the IDF said.

Israeli forces also "located intelligence materials and large quantities of weapons" during the night operation, the IDF said.

More than 810,000 people have fled Rafah in the past two weeks amid Israel's ongoing military operation in the southern Gaza city, according to the United Nations Relief and Works Agency for Palestine Refugees (UNRWA).

"Every time families are displaced their lives are at serious risk. People are forced to leave everything behind looking for safety. But, there's no safe zone," UNRWA said on X Monday.

Congress is considering sanctioning the International Criminal Court regarding the arrest warrants for Prime Minister Benjamin Netanyahu and Defense Minister Yoav Gallant, according to House Speaker Mike Johnson.

“In the absence of leadership from the White House, Congress is reviewing all options, including sanctions, to punish the ICC and ensure its leadership faces consequences if they proceed," Johnson said in a statement. "If the ICC is allowed to threaten Israeli leaders, ours could be next."

The ICC has "no authority" over Israel or the U.S., Johnson noted.

-ABC News' Lauren Peller

President Joe Biden called the application for arrest warrants from the International Criminal Court against Israeli Prime Minister Benjamin Netanyahu and other Israeli leaders "outrageous."

"And let me be clear: whatever this prosecutor might imply, there is no equivalence -- none -- between Israel and Hamas," Biden said.

"We will always stand with Israel against threats to its security," Biden's statement said.

The U.S. and Israel are not parties in the ICC.

Sirens sounded in Tel Aviv on Sunday for the first time in months as Hamas' armed wing confirmed it launched a rocket attack on Israel's largest city.

Hamas' armed wing, the Al-Qassam Brigades, released a statement saying it had launched a rocket attack on Tel Aviv from Rafah.

"We bombed Tel Aviv with a large rocket barrage in response to the massacres against civilians," the statement said.

The Hamas fighters also posted an accompanying video showing what appeared to be rocket trails in the sky.

Israel Defense Forces said sirens sounded across central Israel Sunday after "eight projectiles were identified crossing from the area of Rafah into Israeli territory.

"A number of the projectiles were intercepted by the IDF Aerial Defense Array," the IDF statement said.

Israel's National Emergency Medical Service (MDA) said it received no reports of serious injuries.

"Following the Red Alert sirens heard in the center of the country: MDA teams did not locate casualties at any of the scenes, except for a patient who was lightly injured on the way to the protected space, and a number of victims with stress symptoms," the MDA said in a statement.

The IDF said later Sunday that it conducted an airstrike on the area where rocket launchers were used to direct rockets toward Tel Aviv, which the IDF said in a statement was "situated near two mosques in the area of Rafah."

Hamas has launched rocket attacks toward the areas around Gaza throughout the war but has not launched longer-range rockets in months. Sirens had not sounded in Tel Aviv in four months from Gaza-related rocket attacks.

-ABC News' Victoria Beaule