Federal authorities are looking into reports that a hateful message targeting U.S. Rep. Ilhan Omar was scrawled onto a bathroom stall at a Twin Cities gas station.

The message, written in black marker in the men's room, read: "Assassinate Ilhan Omar."

It came to the attention of customer Brian Raines, who had stopped by his local Holiday gas station in Rogers on Feb. 22.

Raines, a father of two children and a U.S. Navy veteran, said he asked the manager why he hadn't covered up the message. Raines said the manager seemed annoyed by the question, rolled his eyes, and responded that he was waiting for the corporate office to send out a painter.

"I said, 'You didn't think about covering it up yourself?' " Raines recalled. "You don't need a painter to come out on a Saturday to do the right thing."

Raines said he walked back to his truck, still bothered by what he experienced. So he pulled up a picture he took of the message and posted it to his Instagram page, predicting — correctly — he would be trolled by people accusing him of making it up.

The post didn't gain much traction until Omar tweeted it Friday afternoon.

Raines said more people need to come forward and shed light about hateful, racist or anti-Islamic rhetoric they hear in their communities.

"If we don't take a stand and we don't put our name to this stuff, and we don't stand up and be principled, this stuff is just going to continue to flourish," Raines said. "I don't want a bunch of white nationalists with tiki torches marching down my street. This kind of stuff just has to stop."

Raines said he has never met the Democratic congresswoman, who last fall became the first Somali-American elected to Congress. He suspects whoever wrote the message is targeting her because she's Muslim, black and a refugee. Raines said even if people disagree with Omar's politics, attacking her with such venomous speech is not acceptable.

"In this country, we just don't call for the assassination of legally and duly elected officials," Raines said.

On Saturday, Kevin Smith, a spokesperson with the FBI's Minneapolis division, said the bureau was aware of the Instagram post and was looking into it along with other agencies. Raines said no one from law enforcement, nor from Holiday's corporate offices, has contacted him.

Raines revisited the Holiday men's room Friday night and said the writing is now concealed with a smear of white paint and some black duct tape. A man who answered the phone Saturday at the store declined to comment to MPR News.

Earlier this week, Omar was targeted in an anti-Muslim display at the state capitol in West Virginia. The state Republican Party's display included a poster falsely linking Omar to the 9/11 attacks. Omar tweeted about both incidents Friday.

She's also been in the spotlight this week for again offending Jewish leaders after she made comments about Israel that some are calling anti-Semitic. Critics say she rehashed old stereotypes questioning the patriotism of Jewish American when she spoke at a forum Wednesday night in Washington D.C. with Rep. Rashida Tlaib of Michigan.