Two animal rights activists have been charged with terrorising the fur industry during cross-country road trips in the US, in which they released about 5,740 minks from farms and vandalised the homes and businesses of industry members, the FBI said.

The FBI's Joint Terrorism Task Force arrested Joseph Brian Buddenberg, 31, and Nicole Juanita Kissane, 28, both of Oakland, California, and federal prosecutors charged them with conspiracy to violate the Animal Enterprise Terrorism Act.

A federal grand jury indictment, released on Friday, said the two caused hundreds of thousands of dollars in damages during 64,000km of cross-country trips over the summer and into the autumn of 2013.

"Whatever your feelings about the fur industry, there are legal ways to make your opinions known," US Attorney Laura Duffy said in a statement.

"The conduct alleged here, sneaking around at night, stealing property and vandalising homes and businesses with acid, glue, and chemicals, is a form of domestic terrorism and cannot be permitted to continue."

Buddenberg and Kissane allegedly sneaked onto farms in Idaho, Iowa, Pennsylvania, Wisconsin and Minnesota and freed mink and destroyed breeding records. In one case, they released a bobcat from a farm in Montana, according to the FBI.

Vandalising property

They allegedly slashed vehicles' tires, glued businesses' locks or smashed windows, vandalising property in San Diego, Spring Valley and La Mesa, California. They are also charged with attempting to flood the Sun Prairie, Wisconsin, home of an employee of the North American Fur Auctions.

The indictment states that they covered their tracks by avoiding phones or logging into known online accounts and email. Instead, they used internet on public computers and encrypted email and cash for purchases while travelling. They would allegedly withdraw hundreds of dollars while back home in the San Francisco Bay Area before another trip.

The FBI states that they drafted communiques and posted them online to publicise their actions on websites associated with "animal rights extremists".

The two were under house arrest with electronic monitoring until a scheduled court date on Tuesday, the AP news agency reported. It was not clear whether either has hired an attorney.

If convicted, they each face a maximum of 10 years in prison and a $250,000 fine.