The Americans arrested when buying weapons on Thursday, on suspicion of planning terror attacks on New York synagogues, were apparently angry that the world treated Muslims "like dogs".
Ahmed Ferhani, a 26-year-old said to be of Algerian descent, was heard by undercover police saying that he needed the arms "for the cause" and expressing interest in attacking the Empire State Building.
Mr Ferhani also boasted that he and Mohamed Mamdouh, a 20-year-old of Moroccan descent, would be "victorious" in their attempt.
The pair were detained attempting to buy AK-47s, hand grenades and other weapons. According to police, Mr Fehrani was considering posing as an Orthodox Jew in order to carry out the attack.
