A threat sent to a New York mosque was signed by someone calling themselves the 'Muslim slayer'.
The American Turkish Eyup Sultan Cultural Centre in Brooklyn received the threatening note on Tuesday (28 February), Imam Ibrahim Yavas told the police.
New York's hate crimes task force is investigating the letter, which reportedly claimed the writer fantasized about killing non-white people, including the imam at the mosque, The Star Tribune reported.
In addition, the Associated press reported the writer claimed he had a "dirty little secret".
No arrests have been made in the case, which the Council of American Islamic Relations highlighted, telling its members in a video "we must stand up for each other".
The incident is not the first in which a mosque in the US has received a threatening letter, while many Muslims in the US have reported they feel less safe following such incidents.
In addition, incidents of Muslim hate crime including women in hijabs being targeted, have been reported in a number of places around the country. Several weeks ago, Louisiana police launched an investigation after anti-Muslim flyers were pasted on a mosque in Bosque City.
The letter-sized flyers, which were stuck on the side and front door of the Masjid Al Noor Bossier City mosque building, read: "Imagine a Muslim-free America".
Following the incident, the Council on American-Islamic Relations (CAIR) requested the matter be investigated as a hate crime, KSLA News 12 reported.
The council also said the flyers mentioned the name America Vanguard, which the Southern Poverty Law Center identifies as a white supremacist group, and whose website mentioned white nationalism.