NAHALIN, West Bank — Brad Lander, a Democratic congressional nominee from New York, was among roughly 80 Americans and Israelis detained by Israeli security forces Wednesday while helping Palestinian families harvest olives near the settlement of Beitar Illit. The group included rabbis and activists from the U.S. organization T’ruah and the Israeli group Rabbis for Human Rights. After about two hours at the grove, drones circled overhead and Israeli forces arrived, declared the area a closed military zone and took the group to a police station for questioning. Israeli authorities had not publicly said what the group was suspected of doing. Israel’s military and police did not immediately comment. “We've been detained by the Israeli military for harvesting olives, and let's be clear: Occupation is a crime under international law,” Lander said in a video recorded aboard a bus transporting the detainees. “Harvesting olives is not a crime under any law.” Two Israeli lawyers who work on such cases described the detention as the largest mass detention of activists in the occupied West Bank in at least a decade. Rabbi Arik Asherman, a longtime Israeli human-rights advocate, called it “unprecedented.” The olive harvest is important to Palestinian families culturally and economically. Palestinians in the area said they have struggled to reach their groves since the Hamas-led Oct. 7, 2023, attack on Israel, citing danger from rising settler attacks. The detentions came less than a week after U.S. photojournalist Heidi Levine was assaulted by Israeli settlers while covering the harvest in another West Bank village. In July, Democratic Rep. Ro Khanna of California was briefly detained during a visit to the territory. The activists said they joined the Palestinian farmers in hopes their presence would help them harvest safely. The circumstances of the latest detentions—and whether any charges will follow—were not immediately clear.