Seventy people were killed and 200 were injured in an Israeli strike on a convoy of civilians heading from northern Gaza to central Gaza, according to the Palestinian government press office.

-ABC News' Will Gretsky

The first U.S. charter flight to evacuate Americans from Israel has departed the country and is now en route to Europe, John Kirby, spokesperson for the National Security Council, told reporters on Friday. Kirby didn’t provide the exact destination in Europe.

He said more flights are expected to depart "in the coming days" and that "the State Department will continue to organize these charter flights for as long as there is a demand from US citizens for departure assistance."

He said the U.S. is still exploring "other options" to expand evacuation capacity, which also includes an option by sea.

Kirby also spoke to the heightened alert across the U.S.

"I want to be completely and crystal clear on one thing: At this time, none of our intelligence agencies have any specific intelligence indicating a threat to the United States stemming from the Hamas terrorist attack in Israel," Kirby stressed.

-ABC News' Justin Gomez

Israeli special forces have been inside Gaza over the last few days trying to locate hostages, according to an Israel Defense Forces spokesperson.

"Infantry and armored forces searched and gathered in the area for findings that may help in the effort to locate the missing and thwarted terrorist infrastructure and terrorist cells found in the area, among which a cell of the terrorist organization Hamas fired anti-tank fire at Israeli territory," the IDF said. Israel's air force is continuing its attacks on Hamas in Gaza, the IDF said.

Israel said its alerted 120 families that their loved ones are held in Gaza.

Reuters videographer Issam Abdallah was killed while providing a live signal in southern Lebanon, Reuters said.

"We are urgently seeking more information, working with authorities in the region, and supporting Issam’s family and colleagues," Reuters said. "Our thoughts are with his family at this terrible time."

Two other Reuters journalists were injured.

Human Rights Watch has accused Israel of using white phosphorus munitions in military operations in Gaza on Wednesday, saying it violated international humanitarian law by putting civilians at unnecessary risk.

In a report released Thursday, Human Rights Watch said it based its determination on a video it said it has verified, as well as two eyewitness accounts.

The Israel Defense Forces said in a statement to ABC News that claims they used white phosphorus in Gaza are "unequivocally false."

ABC News geolocated a video showing a jellyfish-shaped plume of white smoke over the port of Gaza. The video was posted on Wednesday by the official Palestinian news agency WAFA and matches images posted on social media and by other news outlets on the day.

Two experts -- Amael Kotlarski, the weapons team manager for the defense intelligence firm Janes, and Amnesty International weapons investigator Brian Castner -- told ABC News that images suggested munitions deployed over the port of Gaza on Wednesday appeared to contain white phosphorus.

"We have verified that Israeli artillery forces striking Gaza are equipped with M825 and M825A1155mm white phosphorus projectiles," Castner told ABC News, pointing to photographs by an Anadolu Agency photographer taken on Monday and showing Israeli troops handling shells labeled "M825A1."

Kotlarski said visual evidence alone was not sufficient to confirm that these specific shells were used in the Gaza port strikes.

There are "perfectly legal" military uses for white phosphorus munitions, Kotlarski said, including to create a smoke screen to conceal movements, to mark targets for artillery or air strikes, or to illuminate a battlefield. However, its use in urban areas is "problematic due to the higher risk of collateral damage," Kotlarski said, including the munitions' potential to cause severe burns.

White House Principal Deputy Press Secretary Olivia Dalton said Friday the U.S. had not independently verified allegations Israel used white phosphorous "so that is not something I would want to speculate about or weigh in on at this time."

-ABC News' Christopher Looft, Ben Gittleson and Jordana Miller