ANN ARBOR, Mich. (AP) — Authorities months later have filed charges against nine people who are accused of trespassing or resisting police during the May break-up of a pro-Palestinian camp at the University of Michigan.

“The First Amendment does not provide a cover for illegal activity,” Attorney General Dana Nessel said Thursday, a day after charges were filed in Washtenaw County.

The camp on the Diag, known for decades as a site for campus protests, was cleared by police on May 21 after a month. Video posted online showed police using what appeared to be an irritant to spray people, who were forced to retreat.

The university said the camp had become a threat to safety, with overloaded power sources and open flames.

Nessel said two people were charged with trespassing, a misdemeanor, and seven more people were charged with trespassing as well as resisting police, a felony.

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

U.S. Rep. Rashida Tlaib, a Detroit Democrat who supports the protesters, said the charges were “frivolous” and a “shameful attack” on the rights of students.

Separately, Nessel said state prosecutors charged two people for alleged acts during a counter-demonstration on April 25, a few days after the camp was created.

Nessel said authorities still were investigating spring protests at the homes of elected members of the university's governing board.