The Minnesota chapter of the Council on American-Islamic Relations (CAIR-MN) has asked the FBI to investigate a threatening e-mail warning that “millions of patriots” are armed to the teeth.

“Get ready to have a war,” the e-mail reads.

Jaylani Hussein, CAIR-MN executive director, said the e-mail received Thursday evening is the second one from the same sender. The first one in December was a one-sentence e-mail that Hussein classified as hate mail.

“Now he’s threatening,” he said, noting it also was sent to the organization’s Southern California chapter. This one rattled CAIR’s staff because it’s the second one, indicating the sender is following the organization, he said.

The subject line of the e-mail, laden with obscenities, is “Muslim sewer rats.”

Hussein said his chapter receives at least one piece of hate mail or call every week, including some with vague threats. “We just ignore those,” he said.

But each year the organization also receives three to four calls, e-mails or letters that are threatening, prompting CAIR to notify law enforcement.

A Minnesota man who mailed a bomb threat in 2015 to a mosque under construction in his Minneapolis neighborhood was sentenced earlier this year to one year in federal prison.