The FBI is not investigating letters sent to mosques in six more states promising to “cleanse” America of Muslims.

Several more mosques in the United States have reported receiving hate-filled letters from California that warned Muslims to leave the country or face genocide.

The identical letters postmarked from the Los Angeles area have now shown up at mosques throughout California and in Ohio, Michigan, Rhode Island, Indiana, Colorado and Georgia.

Los Angeles police have been investigating the letters addressed to “the children of Satan” as a hate incident, but not a crime because it does not contain a specific threat.

Rising Islamophobia concerns US Muslims

The letters appeared to be photocopies of a handwritten note referring to Muslims as “vile and filthy people” and saying that President-elect Donald Trump would do to Muslims what Hitler did to Jews.

The Council on American-Islamic Relations has asked the FBI to investigate.

The FBI said the threats, while inflammatory and awful, did not constitute a hate crime, nor did they pose a threat specific enough to investigate at this point. They added they were monitoring the situation and urged anyone to report such incidents.

Police in Providence, Rhode Island, said they would increase patrols after one of the letters was received at Masjid Al-Kareem.

Faissal Elansari of the Islamic Center of Rhode Island said he felt a wave of hate at his doorstep, WPRI-TV reported.

Envelopes have had a return address in the city the letter was sent from – often 331 Oak St – but are postmarked in Los Angeles or Santa Clarita, a suburb about 30 miles north.

The name above the return address is Reza Khan, said Shehadeh Abdelkarim, president of the Islamic Center of Cleveland, which received one of the letters. He noted that is a Muslim name.

“The person obviously knows a little about Muslim culture,” Abdelkarim said.

The name is bogus, said Sgt Mike Abdeen of the Los Angeles Sheriff’s Department, which is helping Los Angeles police.

Letters have been received at six mosques in California, including Los Angeles, Fresno and San Jose, according to police and Islamic groups. Elsewhere, they have also turned up at mosques in Denver; Ann Arbor, Michigan; Savannah, Georgia; and a school affiliated with an Indianapolis mosque.

Trump’s spokespeople have not responded to a request for comment.