NEW : Six appear in federal court Thursday , a day after they were arrested in raids . Alleged group leader was fatally shot Wednesday after firing at law enforcement agents . FBI says men were members of Ummah , led by former Congressman Frank Brown . Law enforcement sources say Ummah seeks to set up Islamic presence in U.S .
NEW : Six appear in federal court Thursday , a day after they were arrested in raids . Alleged group leader was fatally shot Wednesday after firing at law enforcement agents . FBI says men were members of Ummah , led by former H. Rap Brown . Law enforcement sources say Ummah seeks to set up Islamic state in U.S .