Israel-Gaza updates: Biden speaks with Netanyahu about hostages' release, Gaza humanitarian assistance

Images of Israel's potential ground invasion into Gaza could serve as "a catalyst for various violent actors," the Department of Homeland Security warned in an intelligence assessment on Sunday.

The agency said it's "concerned about lone offenders inspired by or responding to the conflict committing simple, unsophisticated attacks that are difficult to warn of in advance."

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Israel's defense minister says military campaign in Gaza may take months Issa Amro, a Palestinian human rights activist in the West Bank, breaks down what he’s seeing.

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"Some individuals continue to call for violence against Jewish, Muslim, and Arab targets in the United States across various social media platforms," the assessment said. "We continue to be concerned about threats to houses of worship and other institutions."

Domestic extremists, while a concern, have not signaled any "intent to provide facilitation or assistance to any foreign terrorist organizations in the Gulf region, including HAMAS or Hezbollah," the assessment said.

-ABC News' Luke Barr

Israeli forces are "preparing thoroughly for the next step -- a multilateral operation in the air, ground and sea," Israeli Defense Minister Yoav Gallant said Monday.

To the soldiers, Gallant said in Hebrew, "Keep preparing for our operation, it will come soon."

"Do your work, get ready," he said. "We will need you.”

In the last 24 hours, at least 436 people have been killed in Gaza, according to the Gaza Health Authority, which is run by Hamas.

The Gaza death toll has now climbed to 5,087 since Hamas' Oct. 7 attack on Israel, according to the Palestinian Health Authority.

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Threat of wider war grows as humanitarian crisis deepensIsrael launched more air attacks over the weekend as Gaza braces for an expected full-scale ground invasion and clashes intensify along Israel’s northern border with Iranian-backed Hezbollah in Lebanon.

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Ayelet and Or Sella recalled to ABC News the moment they were finally able to embrace their cousins Judith and Natalie Raanan at home in Israel one day after the mother and teenage daughter were released by Hamas kidnappers.

"I realized I hadn't breathed for two weeks," Ayelet said.

"I've never felt a hug this intense in my life," Or added.

But eight of their family members are still being held hostage.

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Family of freed American hostages speak outThirteen members of one family were kidnapped or killed on Oct. 7 in a coordinated attack by Hamas but Americans Judith and Natalie Raanan were released by Hamas over the weekend.

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