Al Qaeda No. 2 Leader is Dead: White House

In another "serious blow" to Al Qaeda, a US drone strike in Pakistan killed its No. 2 leader Abu Yahya al-Libi, who helped steer the terrorist group after Osama bin Laden's death, the White House has confirmed.

Al-Libi's death was "another serious blow to core Al Qaeda," White House spokesman Jay Carney said. "His death is part of the degradation taking place in core Al Qaeda in the last several years."

However, Carney was unable to provide further details. Earlier Tuesday, US officials said that al-Libi was killed by a CIA drone strike in Pakistan launched on June 4, 2012. Al-Libi's death marks one of the most significant blows to Al Qaeda since the US military killed Osama bin Laden in a daring nighttime raid on his hideout in Abbottabad, near Islamabad on May 2, 2011.

Al-Libi was second-in-command behind Al Qaeda leader Ayman al-Zawahiri, who took the helm after bin Laden's death.