Two of them, Ahmed Abdellatif Sherif Mohamed (24) and Youssef Samir Megahed (21), both students at the University of South Florida, have been indicted on explosive charges. They were arrested on a South Carolina highway earlier this month.
They are being charged with transporting "commercial explosive materials" across statelines without a permit or license to do so.
Police say Mohamed had information on car bombs and distributed the information via YouTube to instruct others on bomb making, a possible violation of terrorism statutes.
The charges stem from an Aug. 4 arrest in Goose Creek, South Carolina in which a deputy sheriff allegedly discovered explosive materials in their car after stopping them for speeding. The pair have been held on state charges in the Berkeley County jail since their arrest.
The two reportedly made police officer suspicious during a traffic stop when one of them tried to quickly put away a laptop computer. The computer was seized.
Law enforcement sources say they've reviewed Mohamed and Megahed's phone and computer records, but have not found any evidence that ties the two to terrorist groups or a specific plot.
Reportedly police found a small amount of potassium nitrate, a bomb-making chemical, in the trunk of their car when they were stopped in South Carolina.
The charges would bring stiff penalties for the suspects if they are convicted. They could face a maximum 20-year sentence for the charge of distributing information on explosives, and up to 10 years in prison for the transporting explosive materials charge.
According to officials familiar with the case, Mohamed has been arrested previously in Egypt on terrorism-related charges.