Twelve children between ten and sixteen years old were killed when a rocket hit a football field in Majdal Shams on the Israeli-annexed Golan Heights on Saturday.
The town is mainly inhabited by Arabic-speaking Druze.
"Just like all Israeli citizens, and like many around the world, we were deeply shaken by this horrific act", Netanyahu said during his visit on Monday to Majdal Shams, according to a statement.
"These children are our children. The State of Israel will not, and cannot, let this pass. We will respond, and we will respond strongly", he added.
Protests
When Netanyahu arrived at the site, he was also met with protests. About 200 people gathered outside the barriers chanted "Get out, murderer!", reported the Israeli newspaper Haaretz.
Many of the residents of Majdal Shams do not accept Israel's sovereignty over the Golan Heights, which the country took from Syria during the Six-Day War in 1967 and later annexed.
Israel's military has pointed out Hezbollah as responsible for Saturday's rocket attack. The Lebanon-based Islamist militia group has denied the accusation but has stated that it attacked Israeli military targets the same day.
Daily Bombardment
Analysts have speculated that it may have been a misdirected Hezbollah rocket that hit Majdal Shams. Among others, the EU has called for an independent international investigation into the incident.
Israel and Iran-backed Hezbollah have almost daily bombarded each other across the border since the Gaza War began after the terrorist-stamped Hamas attack on Israel in October last year.
The Golan Heights, which lies on Israel's border with Syria, has a vital military strategic location. During the Six-Day War in 1967, Israel took large parts of the area from Syria, and annexed an area of approximately 1,200 square kilometers in 1981.
Only the US has recognized Israel's sovereignty over the area, a decision made in 2019 by then-President Donald Trump.
Tens of thousands of Syrians and Palestinians fled or were driven out of the Golan Heights following Israel's conquest. But around 23,000 Arabs, mostly Druze, still live in the area. Since Israel's conquest, approximately the same number of Israeli settlers have moved to the area. The settlements are illegal according to international law.
