WASHINGTON — An armed drone operated by the Central Intelligence Agency this week killed a top Qaeda operative responsible for plotting terrorist attacks inside Pakistan, two American officials said on Thursday.

The killing of Abu Hafs al-Shariri occurred Sunday, the 10th anniversary of the Sept. 11 attacks. It is the latest strike in the C.I.A.’s campaign of targeted killings of Qaeda operatives that has intensified under the Obama administration.

The strike comes less than a month after a C.I.A. drone killed Atiyah Abd al-Rahman, a Libyan who was promoted to become Al Qaeda’s second-ranking operative after the death of Osama bin Laden in May. The C.I.A. in recent months has also killed Ilyas Kashmiri, a Pakistani militant commander who worked closely with Al Qaeda’s leadership.

Little is known publicly about Mr. Shariri, a Saudi whom a senior administration official said acted as a liaison between Al Qaeda and the Pakistani Taliban, the group that has directed a wave of attacks against Pakistani government installations and hotels frequented by Westerners. According to an Interpol alert, Mr. Shariri was 33.