Iran struck two communities near Israel's main nuclear research center late Saturday, leaving more than 100 people wounded in the southern part of the country.

The rampage came a day after an 18-year-old Israeli settler was killed in a collision with a Palestinian vehicle in an area near two of the villages attacked.

After three weeks of relative insulation from the raging U.S.-Israeli war with Iran, the explosive impact from an Iranian ballistic missile delivered a grim wake-up call in Arad, a desert town in southern Israel.

An initial inquiry found that the US THAAD interception system was supposed to intercept the missile over Arad but missed. It is currently being examined whether this was due to human error.

TEL AVIV/ARAD >> Southern Israeli towns woke to widespread damage on Sunday after air defences failed to intercept two Iranian missiles overnight that injured scores of civilians in one of the worst attacks of the war so far on Israeli soil.

Over 100 people were injured, including a five-year-old girl, after Iran launched a wave of missile strikes at Southern Israeli cities and came dangerously close to hitting a nuclear facility.

Defense Minister Israel Katz instructed troops to destroy more bridges and buildings in southern Lebanon, stoking worries that Israel could expand a military-controlled buffer zone there.

Follow NBC News for live updates on the latest about the war with Iran, where the U.S. launched bunker buster bombs, while Israel struck Lebanon.

By Alexander Cornwell TEL AVIV, March 22 (Reuters) - Israel's military has been ordered to destroy all bridges over Lebanon's Litani River and to step up the demolition of Lebanese homes near the Israeli border,

Follow real-time developments as the US-Israel war with Iran enters a more dangerous phase, with missile attacks, drone interceptions, naval threats and widening regional spillover pushing the Middle East deeper into crisis.