Twenty-two people were killed and 30 more were injured in an Israeli strike on a school in Gaza City, according to the Hamas-controlled Gaza Ministry of Health.

Civil Defense, the local first responders, said they recovered the bodies of 13 children.

The Israel Defense Forces said in a statement a military strike targeted terrorists who were operational in a "Hamas command and control center."

Video shows rubble strewn in hallways and classrooms turned shelters. A witness told Reuters that women and children were gathered in the yard when two missiles hit the school.

Additional verified video shows first responders gathering body parts from under rubble, along with toddlers with severed limbs being tended to.

-ABC News' Victoria Beaule

The Israeli military on Saturday began strikes within Lebanon that were aimed at targets belonging to the Hezbollah militant group, the Israel Defense Forces said.

Thirty-one people were killed and 68 were injured in Israel's strike on Friday in Beirut, the Lebanese Health Ministry said Saturday.

Among the dead are three children -- ages 4, 6 and 10 -- and seven women, the ministry said during a press conference. Three Syrian nationals were also killed, it said.

Among the wounded, 53 have been discharged from hospital. Two remain in critical condition, the ministry said.

Rescue teams were on Saturday morning still searching the rubble searching for additional bodies. The health multiple buildings and cars were damaged and destroyed in the strike.

The Israel Defense Force described the strike on Friday as a "targeted" assault, saying it killed a key Hezbollah commander, Ibrahim Aqil, along with his chain of command.

-ABC News' Ghazi Balkiz, Nasser Atta, Emma Ogao and Victoria Beaule

The Israeli strike on Beirut on the heels of pager and walkie-talkie explosions this week are designed to emphasize to Hezbollah and Iran the depth of the security breach Israel has achieved, two intelligence sources told ABC News.

The sentiment is if the Israelis can plant exploding pagers and radios, they could have already placed sources and devices that reveal key info and personnel in places thought to be protected, sources said.

The Israelis could well be trying to soften the ground for an assault, but the sources believe the consequence of this week’s events could actually be a realization by Iran and Hezbollah that a return to the uneasy status quo on the northern border might be the right move right now.

Prior to the pager explosions, Israeli intelligence had been running out of actionable information about locations and patterns of life among top Hezbollah officials. Learning where the pagers and radios were and who had them created an invaluable trove of intel.

-ABC News' Josh Margolin