Federal law enforcement officers are cracking down on protesters in Portland, Oregon, under the Trump administration’s new executive order to protect US monuments in what the state’s Democratic governor has called “political theatre”.

Multiple videos posted online show camouflage-clad officers without clear identification badges using force and unmarked vehicles to transport arrested protesters.

“It’s kidnapping people!” one person said off-camera, as officers marched a protester away.

A US Customs and Border Protection (CBP) spokeswoman said on Friday agents had been deployed to Portland to support a newly launched US department of homeland security (DHS) unit, tasked with enforcing last month's executive order from Republican President Donald Trump to protect federal monuments and buildings.

The spokeswoman did not provide details, saying it could jeopardise the safety of agents, but said they had been trained for operations “in chaotic environments”.

In addition to Border Patrol agents, Immigration and Customs Enforcement officers are helping DHS’s Federal Protective Service, which provides security for federal buildings, ICE said.

Oregon governor Kate Brown called it “a blatant abuse of power by the federal government”. Reuters