Israel-Gaza updates: US is 'strengthening' military force in Middle East

Hamas confirmed that Samer Mahmoud al-Haj, one of its local commanders, was killed in an Israeli attack on the Lebanese city of Saida. Although the commander is not high-ranked, his killing has triggered protests in Ayn al-Hilweh, which is the biggest Palestinian refugee camp in Lebanon.

The Israeli Defense Forces confirmed the attack in a statement, saying al-Haj was responsible for advancing terror attacks and projectile launches from Lebanon toward Israeli territory.

"Samer operated as the military forces' commander in the Ain al-Hilweh camp located in the area of Sidon and was responsible for the recruitment and training of terrorists to attack the State of Israel," the IDF said in a statement.

-ABC News' Nasser Atta and Bruno Nota

For at least the fourth time in the past month, the Israel Defense Forces raided the eastern part of Khan Younis in the southern Gaza Strip. Israeli forces have killed at least 29 people in the central and southern areas of Gaza so far on Friday, including 19 in Khan Younis, according to Gaza's Hamas-run Ministry of Health.

The IDF ordered civilians east of Khan Younis to evacuate Thursday. On Friday morning, the IDF announced that its troops have begun "operational activity in the Khan Younis area" after receiving "intelligence indicating the presence of terrorists and terror infrastructure."

The IDF withdrew from the east of Khan Younis just 10 days ago.

Since dawn on Friday, there have been dozens of bombardments and shelling in various areas across war-torn Gaza, including the southern city of Khan Younis. The hardest-hit areas were Al-Maghazi camp, east of Al-Nuseirat camp; the eastern areas of Khan Younis; Bait Lahia in the north of Gaza; and Zaytoon neighborhood in the east of Gaza City.

At least 23 people have been killed in the central and southern areas of Gaza so far on Friday, according to Gaza's Hamas-run Ministry of Health.

A senior U.S. official told ABC News on Thursday that the call from President Joe Biden, the ‎‏Egyptian President and the Qatari Amir for Israel and Hamas to return to the negotiating table to work out a cease-fire deal was a step forward, despite more work needing to be done.

"It's not like the agreement is going to be ready to be signed on Thursday," the official said. "There's still a significant amount of work to do, but we do believe that what's left here really can be bridged, and there's really just no time to lose," the official added.

The official said that both Israel and Hamas have "very firm positions" on "about four or five issues" each. And though the official said they might seem to be "unbridgeable," they have been able to find a way forward working through the issues one by one.

"We are determined to do all that we possibly can, recognizing that lives are on the line," the official added.

-ABC News' Michelle Stoddart

In a joint statement, leaders from the U.S., Egypt and Qatar called on Israel and Hamas to resume discussions on Gaza.

The statement -- signed by President Joe Biden, Egyptian President Abdel Fattah el-Sisi and Amir Sheikh Tamim Bin Hamad Al-Thani of Qatar -- called for both sides to meet in Doha or Cairo on Aug. 15.

"‎‏It is time to bring immediate relief both to the long-suffering people of Gaza as well as the long-suffering hostages and their families," the statement read. "The time has come to conclude the ceasefire and hostages and detainees release deal."