The group had joined farmers in an olive grove outside the Palestinian village of Nahalin. After about two hours, drones circled overhead and Israeli security forces declared the area a closed military zone, then escorted and detained the activists for questioning, according to accounts from the scene. It was not clear what authorities alleged the group had done. Israel’s military and police had not commented at the time of publication.

In a video recorded aboard a bus taking the group to a police station, Lander said they had been detained for harvesting olives. “Harvesting olives is not a crime under any law,” he said, also describing the occupation as a violation of international law.

Two Israeli lawyers who handle such cases said the detentions were the largest mass detention of activists in the occupied West Bank in at least a decade. Israeli human-rights advocate Rabbi Arik Asherman called them “unprecedented.”

The activists included members of the U.S. group T’ruah and the Israeli organization Rabbis for Human Rights. They said their presence was intended to help Palestinian families harvest safely.

Olive harvesting is both an important cultural tradition and a source of income for Palestinian families. Farmers have faced growing obstacles reaching their land. Several Palestinians have said they have been unable to harvest their trees since the Hamas-led attack on Israel on Oct. 7, 2023, citing increased danger from settler attacks.

The detentions followed an assault less than a week earlier on U.S. photojournalist Heidi Levine, who was covering Palestinian farmers harvesting olives in the West Bank. In July, California Democratic Rep. Ro Khanna was also briefly detained during a visit to the territory.