The military, announcing the incident on Tuesday, provided no additional details about the man's identity, his motive, or whether he was carrying anything at the time of his detention.
Israeli state broadcaster Kan 11 reported that surveillance identified the suspect crossing the border and that troops were dispatched to the scene to arrest him. Israeli outlet Ynet said the military was treating the incident seriously and that it was under investigation.
Nitzana is a small community in southern Israel's western Negev Desert, directly adjacent to the Egyptian border opposite the Al-Awja area on the Egyptian side. The Nitzana border crossing, also known as the Eliav crossing, primarily handles cargo transport rather than serving as a major passenger channel. It lies roughly 75 km (47 miles) south of Beersheba.
Egyptian officials have not publicly commented on the detention.
The incident occurred as Israel maintains heightened alert levels along the Egyptian border. Drug and arms smuggling takes place across the border between Egypt and Israel, neighbouring countries that signed a peace treaty in 1979 but whose relationship remains largely chilly. Ynet reported that the crossing came less than a year after Israel's defence minister ordered the area adjacent to the Egyptian border declared a closed military zone and announced changes to open-fire regulations following earlier smuggling activity.