Pro-Palestinian protesters wearing masks pitched tents and placed fake bloody corpses outside the home of a University of Michigan board member Wednesday, raising tension with the school.

Sarah Hubbard, chair of the university’s governing board, said the 6 a.m. demonstration at her home in Okemos involved 30 people.

“They approached my home and taped a letter to my front door and proceeded to erect the tents. A variety of other things were left in the front yard,” Hubbard told The Associated Press. “They started chanting with their bullhorn and pounding on a drum in my otherwise quiet neighborhood.”

She and her husband stayed inside. Okemos is 60 miles (100 kilometers) from the Ann Arbor campus.

The protesters left 30 to 45 minutes later when Meridian Township police arrived, Hubbard said. No arrests were made. Three tents and fake corpses wrapped in sheets were left behind.

Protesters at the Ann Arbor campus have an encampment on the Diag, a prominent public space.

The group is demanding that the university’s endowment stop investing in companies with ties to Israel. But the university insists it has no direct investments and only less than $15 million placed with funds that might include companies in Israel. That’s less than 0.1% of the total endowment.

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“There’s nothing to talk about. That issue is settled,” Hubbard said.

In social media posts, a coalition calling for divestment acknowledged the protest and said it would “remain relentless in the struggle for a free Palestine.”

“Please stop complaining on Twitter and come to the encampment to actually negotiate,” the group said, referring to Hubbard.

The university said the protest at her home was not free speech. “The tactics used today represent a significant and dangerous escalation,” the university said.

School officials have not disclosed any plans to break up the encampment on campus, which was created in April.

“We would prefer that they would leave on their own,” Hubbard said.