DES MOINES —Three demonstrators were arrested after picketing in front of an Office Max Thursday.

Police were called after a man tripped over a protester and filed an incident report with Office Max, 2700 Ingersoll Ave.

The man, David, 57, who refused to release his surname, said his knee, hip, elbow and hands were injured when he fell.

Office Max would not release the man’s name and deferred comment to a national office.

“It seemed to me something moved when I walked by,” said David, referring to the cross-legged protesters in front of the door.

What angered him, he said, was that none of the protesters asked if he was all right after the fall.

“I just think I’m more important than a tree,” he said.

Trees were more important to the protesters, however.

More than 20 Grinnell College students gathered in the rain to chant and sing. Three of them — Shana Ortman, Linda Wells and Lisa Stevens — were chained together as they sat in front of the store.

“We’re not leaving until Office Max stops degrading life on Earth by selling our endangered forests,” Ortman said.

The students were opposed to Office Max stores, whom they said had not adopted a “Responsible Paper” policy like competitor chain Staples.

Activists called for the chain to phase out its use of paper and products made from endangered forests and move toward post-consumer recycled products.

When police arrived, protesters were chanting “Office Max, now’s the time — Stop committing eco-crime.”

Five cruisers responded to the call, bearing six officers. The officers proceeded into the Office Max store to talk to managers and the man claiming injury.

The man who fell did not press charges, but the police asked the protesters to leave after the incident. All but the three chained students complied.

Officers then attempted to cut the chains and locks. The chains held but the police persisted, eventually wrangling the trio free from their bonds.

When released, the students were told they were not under arrest and were told to leave.

The students remained, and were then removed by police and taken to the Polk County Jail on charges of criminal trespassing.