Soon after the New York Times declared the Benghazi attack to be the work of Ansar al-Sharia (which has been linked to al-Qaeda) and not al-Qaeda, the State Department is planning to designate three branches of Ansar al-Sharia — including the Benghazi one — as foreign terrorist organizations in the coming days.

That’s nearly 16 months since the deadly attack on the U.S. diplomatic facility in Benghazi. Directly after the attack, the State Department Operations Center had alerted senior department officials and the White House that Ansar al-Sharia had claimed responsibility on Facebook and Twitter.

“I welcome this morning’s report that Ansar al-Sharia will soon be designated by the State Department as a foreign terrorist organization,” said House Foreign Affairs Committee Chairman Ed Royce (R-Calif.). “Sixteen months after the terrorist attacks in Benghazi, the administration is confirming what it has long known – that Ansar al-Sharia carried out an attack against the United States that killed four Americans in Benghazi, Libya.”

“The Obama administration should be doing all it can to hunt down those responsible for this terrorist attack,” Royce added. “I’m gravely concerned that they are not.”

The Washington Post reported that a former Guantanamo Bay detainee, Abu Sufian bin Qumu, is suspected of participating in the attack that killed four Americans.

Qumu was released from Gitmo to Libya, where the Gadhafi regime freed him in 2008.