(CNN) -- Three men authorities said were found with about 1,000 untraceable cell phones were arraigned Saturday on terror-related charges, and were believed to have been targeting a Michigan bridge, a prosecutor said.
"The targeted issue in this case was the Mackinac Bridge. That is what we have information on," Tuscola County prosecutor Mark Reene said.
The bridge is 5 miles long and connects Michigan's upper and lower peninsulas.
Police in Caro, Michigan, said the men were arrested early Friday and were being held on charges of "providing material support for terrorism and obtaining information of a vulnerable target for the purposes of terrorism."
The suspects are two brothers, Adham Othman, 22, and Louai Othman, 23, and their 19-year-old cousin, Maruwan Muhareb, CNN affiliate WEYI reported.
No pleas were entered at the arraignment Saturday at a District Court in Caro, according to The Associated Press.
A magistrate set bond at $750,000 for each suspect and the men were being held at the Tuscola County Jail, police told the AP.
"Based on information received from a variety of agencies, we're developing how the actual telephones were sold and revenue was passed from one location to the next, and obviously it's fairly complex," Reene said.
The men each had a Texas driver's license and said they had traveled to Michigan to buy the phones, which they were planning to resell for profit in the Lone Star state, police said.
Officers were dispatched early Friday when the men aroused suspicion at a Caro Wal-Mart, where they purchased 80 prepaid wireless "TracFones" with cash, Caro Police Chief Ben Page said.
Police intercepted the men in the store's parking lot and found nearly 1,000 cell phones in the trio's rented minivan, authorities said. The phones were in boxes and had been removed from their packages with the phone batteries in separate boxes, Page said.
Authorities believe the men were either selling the phones to make money for terrorism or using them for explosives, WEYI reported.
The wife of one of the men told the AP her husband and his relatives are not terrorists, but are simply trying to make money by reselling cell phones.
Lina Odeh, wife of Louai Othman, said the men were buying the phones to sell to a man in Dallas for a profit of about $5 per phone, the AP reported.
She said they were in Michigan because so many people in the Dallas area are doing the same thing that the phones are often sold out.
The men also claimed to have been in Wisconsin and other states, and police were in the process of confirming that, Reene said.
Police have released few other details about the case.
A pretrial hearing has been set for Friday and a preliminary exam for August 24, the AP reported.