Eight people were arrested Wednesday morning outside of the U.S. Immigration and Customs Enforcement building on Southwest Macadam Avenue after federal police shot pepper balls at a group of protesters whose arms were linked to block a van from leaving the facility's driveway.

Video of the chaotic scene shows at least eight people standing arm-in-arm refusing to comply with officers' orders to clear the driveway.

According to tweets from protesters, the group was attempting to block the exit of a "deportation bus" that would take immigrant detainees from the Portland ICE building to another detention center. Federal officials say the protesters violated an agreement "between their organizers, the Federal Protective Service, and others."

A group of Department of Homeland Security agents walked up and grabbed some of the protesters and began attempting to pull them apart. Then, another federal officer with a pepper-ball rifle opened fire on the group from a few feet away.

Federal Protective Services spokesman Robert Sperling said in a statement that other protesters had thrown "various items thrown at them including an unknown liquid, boards with protruding nails, and other items" at the officers.

Sperling could not share evidence that protesters had thrown liquid or boards at federal police.

He also said that breaking up the protest group "ultimately requir[ed] the deployment of pepper ball and pepper spray to keep others back and to protect the arresting officers." He did not explain why officers also fired pepper balls at the protesters blocking the entrance other than to say it was necessary to break up their blockade after protesters refused to comply with orders to move.

When asked whether officers acted within DHS policy by opening fire on protesters who were passively resisting officers' orders by linking arms and refusing to move, Sperling declined to answer and then hung up the phone.

WW called him back. Asked follow up questions, Sperling said that "it is within policy after a number of verbal warnings to escalate."

He says the protesters with linked arms committed a violation by refusing to comply with officers' orders.

"I know my officers acted within policy and with due diligence and followed the letter of the law," he says.