Spokeswoman Rabiah Ahmed of the Council on American-Islamic Relations said the national organization has received dozens of calls reporting incidents, the South Florida Sun-Sentinel reported Friday.
Monday morning, a worker found a break-in and vandalism at the Al-Ihasen mosque in Perrine, south of Miami. Nothing was stolen.
The caretaker of the Islamic School of Miami discovered an expletive and reverse swastika spray-painted on the school's sign Wednesday.
Also Wednesday, Maulana Shafayat Mohamed of the Darul Uloom Institute in Pembroke Pines, received a letter that said "Kill them all in the name of Allah."
He said the letter would have no impact on his campaign against violence, nor would the prisoner abuse in Abu Ghraib prison or the beheading of Nick Berg.
"They may be soldiers, but what they did is not the voice of America. Similarly, the guys who beheaded Berg, they may be Muslims, but they do not represent Islam and the voice of all Muslims," Mohamed said.