Students at a growing number of U.S. colleges are gathering in protest encampments with a unified demand of their schools: Stop doing business with Israel — or any companies that support its ongoing war in Gaza.

The demand has its roots in the Boycott, Divestment and Sanctions movement, a decades-old campaign against Israel’s policies toward the Palestinians. The movement has taken on new strength as the Israel-Hamas war surpasses the six-month mark and stories of suffering in Gaza have sparked international calls for a cease-fire.

Inspired by ongoing protests and the arrests last week of more than 100 students at Columbia University, students from Massachusetts to California are now gathering by the hundreds on campuses, setting up tent camps and pledging to stay put until their demands are met.