Updated

Authorities filed federal charges Friday against three African refugees after an item first thought to be a bomb was found in one of their carry-on bags at Phoenix's airport.

Luwiza Daman, 51, Shullu Gorado, 25, and Shani Asa, 34, face federal charges of possessing a package that appeared to be an explosive device. They had been charged in a local court with having a hoax device and conspiracy to obtain a hoax device, although it was unclear Friday whether those counts were still pending.

Daman, Gorado and Asa were being held until a hearing Tuesday in federal court. They have declined to speak to The Associated Press and it was unclear whether they have lawyers.

The three are from Eritrea, a small country on the Red Sea in the Horn of Africa, and are described by authorities as acquaintances. Daman was living in Des Moines, Iowa, while Gorado and Asa were living in separate apartments in Phoenix.

Daman was carrying the suspicious item in her carry-on bag Aug. 5 as she went through a security checkpoint at Phoenix Sky Harbor International Airport to board a plane to Des Moines, Phoenix police Sgt. Steve Martos said.

Asa gave the item to Gorado, who gave it to Daman to take to Des Moines, Martos said.

The sergeant described the package earlier this week as an organic substance inside a container, with a cellphone taped to the outside. An investigative report the FBI released Friday describes the item in better detail as a box of a paste-like dessert with a red cellphone taped face-down to the lid with medical-type tape.

"The object was similar in appearance to an explosive device, although it lacked the wires necessary to form a complete explosive device," FBI agent Benjamin Oesterle wrote in the report.

Asa told investigators he wanted Daman to take the package to his brother in Des Moines because he didn't have a cellphone, Oesterle wrote. Asa said he put tape around the phone because it was broken, the report said.

But agents at the airport said the phone was in working order and the tape wasn't being used to keep it together, Oesterle said. He also wrote that Asa's brother told investigators he had a new cellphone for the past five or six months.

FBI spokesman Manuel Johnson said Friday that he couldn't say whether the agency believed Daman, Gorado and Asa were testing airport security, something that police officers and Oesterle wrote was a possibility.

A responding Phoenix officer reported, "The suspicious package suggests subjects were testing airport security protocol."

Oesterle wrote, "The successful transit of such an object through a TSA security checkpoint would reveal potential weaknesses in the security screening methods employed in United States airports."

Oesterle's report also said he knew of a similar incident involving "an electronic device taped to plastic containers filled with an organic substance" that was placed in checked baggage at the Memphis, Tenn., airport on July 29, the same day Daman had arrived in Phoenix.

___

Follow Amanda Lee Myers on Twitter at http://twitter.com/AmandaLeeAP