Updated

Egyptian authorities have detained the alleged ringleader of an Egyptian terrorist network whose members are suspected of participating in the September attack on a U.S. consulate in Libya that killed a U.S. ambassador and three other Americans, U.S. officials said.

The apprehension of Muhammad Jamal Abu Ahmad removes a man who Western counterterrorism officials consider one of the most menacing operatives to emerge in the region in the wake of the Arab Spring.

His capture would blunt what authorities say are his efforts to launch a new wing of Al Qaeda. The move also shows a willingness by Egypt's Muslim Brotherhood-aligned government to pursue Al Qaeda-associated terrorists, counterterrorism specialists say.

Ahmad, a former Egyptian Islamic Jihad member who was released from prison in Egypt in the wake of last year's ouster of then-President Hosni Mubarak, was apprehended within roughly the past week, officials said.

U.S. intelligence aided in his capture, an official said. It couldn't be learned how or where he was caught.

Since his release in March 2011, Mr. Ahmad has been assembling a new terrorist network with training camps in Libya and Egypt, U.S. officials say, referring to it as the Jamal Network. He also secured financing from Al Qaeda's branch in Yemen, U.S. officials say.

U.S. officials haven't had access to Ahmad. U.S. intelligence officials have been tracking him for the past several months, since he petitioned Al Qaeda leader Ayman al Zawahiri to establish a new Qaeda affiliate he called Al Qaeda in Egypt. He is believed to be about 45 years old.

U.S. interest in Ahmad intensified after U.S. intelligence officials identified operatives from his network at the scene of the fatal attack at the U.S. consulate in Benghazi, officials say.

Ahmad's capture is "strategically important" to the U.S., said Seth Jones, an al Qaeda specialist with the Rand Corp. think tank, because his network's alleged involvement in the Benghazi attacks showed his reach extended beyond Egypt, and more broadly into North Africa. His petitioning to become a new Al Qaeda branch suggested more international aspirations, U.S. officials said.

Ahmad's terrorist aspirations closer to home appear to have put him in Egyptian authorities' sights.

In October, Egyptian authorities raided an apartment complex in Cairo's Nasr City neighborhood and arrested five suspects after a firefight in which one suspect detonated a bomb that set the apartment building ablaze. Authorities alleged that Ahmad was a key funder and possible leader of what they dubbed the Nasr City Cell, according to local reports.

The group was allegedly plotting an attack against the Interior Ministry and other government institutions and individuals. Egyptian authorities also said the cell was connected to Benghazi.

Aside from a possible indirect connection through Ahmad, U.S. officials have said they can't confirm connections between the five men detained in the raid and the Benghazi attacks.

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