WASHINGTON – Testifying out of sight, ex-CIA Director David Petraeus told Congress on Friday that classified intelligence showed the deadly raid on the U.S. Consulate in Libya was a terrorist attack but the administration withheld the suspected role of al-Qaida affiliates to avoid tipping them off.

Petraeus said references to terrorist groups suspected of carrying out the violence were removed from the public explanation of what caused the attack so as not to alert them that U.S. intelligence was on their trail, according to lawmakers.

He also said it initially was unclear whether the militants had infiltrated a demonstration to cover their attack.

Petraeus addressed the House and Senate intelligence committees in back-to-back, closed-door hearings as questions persist over what the Obama administration knew in the immediate aftermath of the Sept. 11 attacks.

After the hearings, lawmakers who questioned Petraeus said he testified that the CIA’s draft talking points in response to the assault on the diplomatic post in Benghazi that killed four Americans referred to it as a terrorist attack. He said that reference was removed from the final version, although he wasn’t sure which federal agency deleted it.