AMNA NAWAZ: Welcome to the "NewsHour."

Israel and Hamas are still locked in heavy combat tonight in Gaza, but much of the day's focus has been on Lebanon.

A top Hamas commander, Saleh al-Arouri, was buried in Beirut after being killed in a suspected Israeli drone strike.

GEOFF BENNETT: That attack on Tuesday sparked fears of a regional war between Israel and the Lebanese militant group Hezbollah, which is an ally of Hamas.

Today, thousands turned out for Arouri's funeral procession waving Palestinian and Hamas flags.

Leaders of Hamas insisted they are undeterred by his death.

AHMAD ABDUL-HADI, Hamas Representative in Lebanon (through translator): This crime will not affect the resistance nor Hamas, because Hamas has lost the best of its martyrs, including its founder, and continued in the resistance, culminating in the October 7 operation.

It will continue, God willing, until liberation and return.

AMNA NAWAZ: Meantime, in Gaza, Israeli forces pressed their offensive, centering on the southern city of Khan Yunis.

The Hamas-run Health Ministry reported another 125 deaths since Wednesday.

And in the occupied West Bank, Israeli troops ended a two-day raid in Tulkarm.

They said they detained hundreds of suspected militants.

The Islamic State group claimed responsibility today for a double suicide bombing in Iran that killed 84 people.

The Sunni extremist group said it struck a blow at Iran's Shiites.

Wednesday's attack targeted crowds honoring general Qasem Soleimani.

He'd been killed in 2020 by an American drone strike in Iraq.

Today, Iranians paid tribute to those killed and 284 others who were wounded.

State officials again vowed revenge.

KAZEM GHARIBABADI, Iranian Deputy Chief of International Affairs of the Judiciary (through translator): We will not be silent until justice is served.

We have various capacities to deal with terrorist groups, and, naturally, we will use all of them, such as intelligence and security capacities and other tools we have for the administration's of justice.

AMNA NAWAZ: The bombing was the worst militant attack inside Iran in decades.

A U.S. drone strike in Iraq killed a top commander of an Iranian-backed militia today.

The Pentagon confirmed it hours later.

The Baghdad attack left a charred hulk of a car.

It followed a spate of attacks on U.S. troops in Iraq and Syria since the Israel-Hamas war began.

In Western Japan, at least 84 people are now confirmed dead after powerful earthquakes this week.

Nearly 180 others are still missing, many of them elderly.

Officials sharply raised that number in the last 24 hours, as soldiers and others continue rescue operations.

Back in this country, a sixth grader was killed and five others were wounded at a school shooting in Iowa today.

Police say a 17-year-old opened fire at the school in Perry, Iowa.

It was the first day back for students after winter break.

The suspected shooter was found dead of an apparent self-inflicted gunshot wound.

Authorities did not provide any information about a possible motive.

Protesters shut down California's State Assembly as they demanded a cease-fire in the Israel-Hamas war.

The action was organized by anti-war Jewish activist groups.

Lawmakers had just convened the year's opening day when they were drowned out by protesters singing and chanting.

Legislative leaders tried to continue, then called a recess and finally adjourned.

On Wall Street, stocks were mostly lower again, as investors awaited the December jobs report due out tomorrow.

The Dow Jones industrial average did gain 10 points to close at 37440, but the Nasdaq fell 82 points.

And the S&P 500 lost 16.

And a 13-year-old Oklahoma boy has reached a pinnacle in the pantheon of video gaming.

Willis Gibson is the first person to beat the original version of Tetris, the Nintendo game involving falling blocks.

His livestreamed video caught the moment last month when the game reached its limit's and crashed and left him stunned.

WILLIS GIBSON, Player: Oh my God.

Oh, my God.

AMNA NAWAZ: Willis' mother says he spends about 20 hours a week playing Tetris.

He also plays competitively and has won about $3,000 to date.

Congratulations, Willis.

Still to come on the "NewsHour": Harvard remains embroiled in controversy after its president is forced out; we speak to the secretary of homeland security about strains on the U.S. immigration system; the remarkable life and legacy of tap-dancing and Broadway star Maurice Hines; plus much more.