Fighting is ongoing in northern Israel near the Lebanon border, where huge plumes of smoke are visible.

The Israel Defense Forces said there was an explosion Friday at the security fence adjacent to Hanita, Israel, which is along the border. The IDF said it's responding with artillery fire toward Lebanon.

"Additionally, an alert was activated concerning the infiltration of terrorists into the community," the IDF said, and Israeli "soldiers are currently searching the area."

The Israel Defense Forces said Hamas is using roofs of residential buildings in Gaza to launch its hostile unmanned aerial vehicles.

Israeli planes have targeted dozens of these launch sites, the IDF said.

"This is further proof Hamas deliberately uses civilian building for military purposes," the IDF said. "The IDF will continue to operate in order to destroy Hamas' hostile UAV capabilities."

In his first on-camera comments about Israel’s evacuation request for northern Gaza, Israeli Defense Minister Yoav Gallant urged Gaza residents to head south. He noted that Hamas will use them as "camouflage," “therefore we need to separate them."

"Those who want to save their life, please go south. We are going to destroy Hamas infrastructures, Hamas headquarters, Hamas military," he said.

Defense Secretary Lloyd Austin, who appeared at the press conference with Gallant, dodged ABC News' question about how Israel could end the Hamas terror threat without inevitably risking civilian lives. Austin called Israel's military "professional" and "disciplined."

Austin described how ISIS had also embedded themselves in civilian populations and how the anti-ISIS coalition "protected civilians and created corridors for humanitarian movement even in the midst of a pretty significant fight. So again, this is a professional force. It is well led, and I have every expectation that it will be disciplined."

Austin added, "I would tell you that in countering ISIS, I felt as if we were staring evil in the eye, it was truly evil. And what we've seen from Hamas, it takes that evil to another level."

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Israel orders evacuation of Northern Gaza

As the bombing of Gaza continues, Israel is calling on hundreds of thousands of people to leave their homes amid fear of an imminent land operation.

-ABC News' Matt Seyler and Luis Martinez

During his meeting in Jordan with Palestinian Authority President Mahmoud Abbas, U.S Secretary of State Antony Blinken conveyed the need to cool tension across the West Bank and prevent the conflict from becoming broader, the State Department said.

“The Secretary extended his condolences to the families of Palestinian civilian victims of this conflict, and reiterated that Hamas does not stand for the Palestinian people's legitimate right to dignity, freedom, justice, and self-determination,” a readout from department spokesperson Matt Miller said.

"The Secretary thanked President Abbas and his team for their work to further calm the situation for the benefit of Palestinians, Israelis, and the tens of thousands of Americans who also call the West Bank home. Secretary Blinken reaffirmed the U.S. commitment to cooperation with the Palestinian leadership and people on efforts to ensure security for all," Miller continued.