Violence between Palestinians and Israelis has been seething for months.

That war also began on the Sabbath, with sirens wailing across the country on Oct. 6, 1973 on Yom Kippur, the holiest day on the Jewish calendar.

On Saturday, many Israelis had been planning to celebrate the holiday of Simchat Torah. Instead, the armed wing of Hamas, the Islamic group that controls Gaza, fired thousands of rockets toward Israel. Simultaneously, reports flooded in of a major breach of Israel’s fortifications along its border with Gaza, the Palestinian coastal enclave that Israel and neighboring Egypt have kept under blockade for 16 years, citing security reasons.

Unverified images soon began to emerge of heavily armed Palestinian militants entering Israeli border communities in pickup trucks, on motorcycles and in at least one case crossing the fenced border by paraglider. Gruesome unverified videos began to circulate, purporting to show the bloodied corpses of Israeli soldiers and of hostages taken into Gaza.

Terrified Israeli residents in border villages phoned in to local television stations from safe rooms. Speaking in whispers, they pleaded for help and said they could hear the militants outside, or even inside, their homes.

As confusion and fear spread, many were asking how the Israeli government and its vaunted military and intelligence services could have been caught by surprise — again. In another echo of the 1973 war, the military scrambled to call up and mobilize military reservists.