Al-Qaeda chief Ayman Al-Zawahiri killed in Afghanistan in US drone strike: Joe Biden

Joe Biden expressed hope that the killing of al-Qaida leader Ayman al-Zawahri brings "one more measure of closure" to families of the victims of September 11, 2001, attacks on the United States. Biden made the comments as he confirmed that a US drone strike in Afghanistan this weekend killed al-Qaida leader Ayman al-Zawahri.