When Tamer Masudin heard sirens go off in his city of Ramat HaSharon on Saturday morning, he immediately got confused.

Was it Remembrance Day, which honors Israel’s fallen military heroes? No, that’s in May, he thought.

So the 26-year-old analyst grabbed his phone and was quickly inundated with pictures and videos of Hamas’ shocking early morning sneak attack that has since sparked a war of unimaginable intensity.

That’s when his thoughts turned to his brother, Samer. The 18-year-old high school student recently had a liver transplant and was convalescing with family in the city of Sderot, just minutes from the Gaza Strip.

“The first thing that came to mind was that I have to save my brother,” Masudin told The Post on Thursday.

“The kid just had a liver transplant, and he was recovering,” he continued. “He was in no shape to run, let alone hide from people.”

“I knew that the moment he stepped out of the apartment — if anyone sees him, he’s going to get shot dead,” he said. “He’ll be gone in, like, a second.”

One might think Masudin’s family might be safe — even during such chaos — because they are ethnic Bedouins, a historically nomadic tribe who have wandered the Middle Eastern deserts for thousands of years.

“We’re traditional Arabs, not very much different than Arabs from the UAE or Saudi Arabia,” he said. “We speak Arabic as our mother tongue, and all of us are Muslims.”

But this attack was different, Masudin said.

Hamas’ rockets never discriminate between Arabs and Jews — they fall where they fall. But the gunmen who raced across the border, butchering and kidnapping as they went, were not particularly discriminating either.

“I saw reports about Hamas terrorists killing Muslims inside of Israel after they infiltrated the border,” he said. “I was terrified the moment I heard the news — extremely terrified.”

Especially because Masudin’s family hails from the Bedouin village of Segev Shalom in southern Israel, just an hour’s drive from the border with Gaza.

“I saw reports about Hamas terrorists killing Muslims inside of Israel after they infiltrated the border,” he said. “I was terrified the moment I heard the news — extremely terrified.”

“All of my family members — my siblings, my parents, my cousins — all of them live in Segev Shalom,” he said. “And some of them are even in the army, or were called into the reserves to serve right now.”

But Sderot was hit particularly hard.

Gunmen burst into the city Saturday morning with their automatic rifles blazing, killing civilians and banging out with local police units in firefights that consumed the town.

They even captured the local police station before reinforcements from the Israel Defense Forces surrounded it and slaughtered the remaining extremists.

Samer was fortunate, however.

Masudin had called the cops, and the military retrieved Samer — after several worrisome days — and delivered him to his mom in Segev Shalom.

But though Masudin’s family narrowly escaped tragedy, many in the Bedouin community did not.