In the early 1980s, agents working for Mossad — Israel's elite intelligence agency — were tasked with smuggling Jewish refugees from Ethiopia to Israel via Sudan.

To do so, they set up a luxurious diving resort in Sudan and posed as hotel staff and diving instructors.

The agents saw to their guests by day and carried out undercover work at night, which involved picking up refugees in camps in Sudan before bringing them across the Red Sea or airlifting them to Israel.

Between 1979 and 1985, the agents managed to save at least 7,000 Jewish refugees.

Photos show how their top-secret operation unfolded.

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In the early 1980s, members of Israel's elite intelligence agency — known as Mossad — were tasked with smuggling thousands of Jewish refugees from Ethiopia to Israel.

A combination of factors, including a deepening food crisis and a bloody civil war, led to a big migration of Jewish refugees, known as Beta Israelis, who wanted to escape to Israel.

But the only way the agents could take the refugees out of Ethiopia was by smuggling them through Sudan and either sailing them across the Red Sea or airlifting them to Israel. It was an operation with plenty of challenges, considering Ethiopian Jews and Mossad agents had to keep their identities hidden.

The solution? Create a luxury beach resort in Arous, an abandoned tourist village in Sudan, as a front for its operations. While agents smuggled refugees out of Sudan by night, they served as hotel staff by day.

Scroll down to read more about their story through photos from "Red Sea Spies: The True Story of Mossad's Fake Diving Resort," a book by Raffi Berg chronicling the resort.