A box containing bricks and rocks was removed from the downtown Minneapolis site of the OccupyMN protest along with a note that described items as supplies for a riot, authorities said.

In response on its Facebook page, OccupyMN organizers denied that any of its participants had anything to do with the box and said it "was brought by an outsider who is not involved [in the protest] nor represents the views or goals of our movement."

The round-the-clock anti-Wall Street demonstration began Oct. 7 at the Hennepin County Government Center with hundreds participating at the outset and a much smaller number pressing on since.

The discovery of the bricks and rocks Monday are "a concern for the safety" of law enforcement personnel and those who visit or work at the Government Center, the Sheriff's Office said in a statement revealing the discovery.

The Sheriff's Office statement did not say where the box came from or whether anyone participating in the protest is responsible. Sheriff's spokeswoman Lisa Kiava added Tuesday that her office "does not view this as a prank."

Paul Walsh • 612-673-4482