The US Department of Homeland Security's Customs and Border Protection arm confirmed on Tuesday it has deployed officers from three paramilitary-style units to join a federal crackdown on protests against police violence in Portland, Oregon.
"We have agents and officers from our special operations groups deployed," a CBP official said in an email. The official did not respond to questions about the number of officers deployed.
Multiple videos posted online showed camouflage-clad officers without clear identification badges using force and unmarked vehicles to transport arrested protesters, tactics that civil-rights advocates said could violate protesters' right to free speech under the First Amendment of the US Constitution.
President Donald Trump, who has been sliding in opinion polls as he seeks re-election, has vowed to also send federal agents to cities including New York, Philadelphia and Chicago, which critics said would amount to a use of federal power for political ends.
CBP, which patrols land borders and operates checkpoints for people arriving at US airports and other transportation hubs, has three specially trained units that have deployed officers to Portland, the official told Reuters.
According to the CBP's website, one of these units, the Border Patrol Tactical Unit, "provides an immediate response capability to emergent and high-risk incidents requiring specialized skills and tactics."
CBP said it also sent agents from its Border Patrol Search, Trauma and Rescue and Special Response teams to Portland.
Senator Ron Wyden, an Oregon Democrat, criticized the Trump administration's deployment of such forces.
"Donald Trump has no justification for deploying paramilitary troops to the streets of Portland or any other American city," Wyden said. "These occupying forces are creating conflict, attacking peaceful protesters and making my hometown more dangerous. For Portland to find peace, Trump needs to pull unwanted federal agents out of our city immediately."