By Kari Huus, msnbc.com Law enforcers in Charlotte, N.C., are looking for the writer of a threatening letter sent to regional mosques detailing ways that an anti-Islam "network" would make life miserable for Muslims, and warning that the writer would not hesitate to kill them if they tried to retaliate On face value it's really a threatening letter. Its like they took a page from the Klans playbook," said Jibril Hough, spokesman for the Islamic Center of Charlotte, which received the four-paragraph letter early last week. "Who knows if this person is part of a greater network, a clandestine conspiracy or just someone who has an active imagination?" The letter claims to represent a network of people in business, government and schools who plan to make life difficult for Muslims by denying them jobs, loans, medical attention and other services. The writer also warned Muslims not to retaliate: "I have no problems killing Muslims legally. So if you try anything, consider yourselves warned," the letter says. Hough said the mosque filed a police report when the letter was first received early last week. He followed up by meeting with the FBI on Monday, and then by reaching out to the local media because he felt it had to be taken seriously. "We are aware of the situation," said Shelley Lynch, public affairs officer for the FBI field office in Charlotte. She added: "Everything about the letter is not as it appears." The letter was signed with a womans name, but an area woman with that name denied having any knowledge of the letter and is working with police in their investigation, according to a report by WSOC TV in Charlotte. Msnbc.com is not identifying the woman in light of uncertainty about her involvement. The Charlotte-Mecklenburg Police Dept. did not respond to multiple calls from msnbc.com for comment and records relating to this case. "We are hoping the authorities will get behind it and find out the motive," said Hough. "We just want the authorities to look at the threat and give it the attention it deserves."