Al-Tahireen was the name of a fictional terrorist cell fabricated by CTU Los Angeles during Day 6. The cell consisted of undercover CTU agents who spoke the language of Abu Fayed, and they claimed to be in touch with Fayed's sponsor General Mohmar Habib.
Six of the Al-Tahireen "terrorists" staged a set-up ambush and mock gunfight with Jack Bauer, Mike Doyle, and another uniformed agent to trick Fayed that he was being rescued. Three of the Al-Tahireen operatives and Fayed's CTU captors acted as if they were killed, and Fayed was extracted by the group's leader Jamal Nasawa, the driver Talit, and Halim.
Jamal explained that their Al-Tahireen cell was answering to General Habib, and attempted to trick Fayed into leading them to the location of the remaining two stolen suitcase nuclear devices. Fayed unexpectedly took a loaded firearm from Halim, but they permitted him to keep it, trusting in the success of their operation. Fayed was cautious about the rescue, and demanded to speak with General Habib to verify Jamal's story. When President Wayne Palmer finally forced the ambassador to get his countrymen to threaten the general, Habib gave Fayed a secret distress code in the form of the name Sameer Al-Afted. The "Al-Tahireen" sting operation was undone, and by the time Nadia Yassir discovered the signal, Fayed had grievously injured Jamal, killed Talit and Halim, and escaped.
Though the "Al-Tahireen" cover was blown, Jack Bauer hid himself underneath Fayed's escape vehicle and soon killed Fayed and his remaining men, securing the two remaining bombs.