A sheriff in rural, coastal Oregon says he's concerned about letters asking residents to to write down the license plate numbers of possible immigrants.

Racist letters mailed to people in Lincoln County advised residents to track and report information about people of color, according to the Lincoln County Sheriff's Office. The letters, titled "The Brown Round-Up Part 1," advised about the kind of information to collect related to people of color, according to a copy of the letter shared by KOIN.

The letter, distributed in Lincoln County, Ore., tells community members to report people who may be undocumented, the sheriff’s office said.

A mayor in Oregon is outraged after he says he received an anonymous letter urging people to help track down suspected illegal immigrants.