Marcelle Ninio, who was imprisoned in Egypt from 1955 to 1968 for her role in a failed Israeli spy operation in 1954, died Oct. 23 in Ramat Gan, Israel, near Tel Aviv. She was 89.

According to an account in the New York Times, Ms. Ninio, who was born in Egypt, was a devoted Zionist. She was working as a secretary in Cairo when she was recruited in 1951 by an Israeli intelligence agent to the secret Unit 131. The outfit was largely dormant until 1954, when Gamal Abdel Nasser seized authority in Egypt after leading the coup that overthrew the monarchy of King Farouk two years earlier. Israel was concerned that Nasser would nationalize the Suez Canal and block access to a critical shipping route. Unit 131’s mission was to detonate bombs to show that Nasser could not protect American and British property or people. The plot failed. She and others were arrested, tried and convicted. She was sentenced to a 15-year term.

In 2005, she and the two other surviving members of what was called Operation Susannah were given military ranks in the Israel Defense Forces for their service to the country.