Members of Ansar al-Sharia, the radical Islamic group blamed for the deadly Benghazi terror attacks, moved in next door to the U.S. compound in Libya months before the assault took place but “nothing was done,” sources tell Fox News.

The anonymous sources say there were several complaints filed about the dangerous new neighbors because they moved into a house just outside the east wall of the U.S. compound about three weeks before American personnel rented the facility. The terrorists then reportedly used the house to plan and participate in the attack on Sept. 11, 2012.

The alarming developments reportedly resulted in repeated request for additional security, weapons and personnel.

AFP/Getty Images

AFP/Getty Images

“We warned D.C. about the guys who moved in next door, but nobody knew what to do and nothing was done,” a U.S. intelligence source said, according to Fox News reporter Adam Housley.

Both a State Department source and U.S. intelligence source reportedly confirmed that American security personnel asked for a “belt-fed mounted machine gun” to put on the roof of the compound — but the requests, too, were repeatedly denied.

State Department spokeswoman Marie Harf called the sources’ claims “dubious” on Monday.

Another State Department source argued there was a security request of some sort being reviewed on the day of the Benghazi attacks, “so to say that the request was rejected is inaccurate.” The same official said the State Department has no record of terrorists moving in next door to the U.S. compound.