PESHAWAR, Pakistan -- Five Taliban commanders -- including the Haqqani network's No. 2 -- were among nine people killed by a U.S. drone strike early Thursday, Pakistani security officials told NBC News.
Maulvi Ahmad Jan, a prominent adviser to Haqqani network leader Sirajuddin Haqqani, was among the dead after a religious school was targeted, according to a security official who was not authorized to speak publicly.
"Initially we thought that a suicide bomber had hit the madrasa but later we confirmed it was a drone attack,” the security official said.
As part of the wider Taliban movement, the Pakistan-based Haqqanis are among the United States' most feared enemies in Afghanistan. They have been blamed for many of the more than 2,000 U.S. military deaths in the country.
Ahmad Jan was a senior commander with the group who did not work out in the field but helped to plan insurgency operations against U.S and Afghan forces according to Dr. Anatol Lieven of King’s College London.
Witness Amjad Hussain said dozens of the militants arrived shortly after the attack, encircling the site.Local residents told NBC News the drone fired four rockets into the madrasa in Pakistan's Waziristan tribal region at 5:40 a.m. local time (7:40 p.m. Wednesday ET).
"The Taliban militants did not allow even local residents to go and see what had happened,” he said. “They blocked nearby streets leading towards the madrassa.”
Taliban commanders Maulana Ghazi Marjan, Maulana Hameedullah, Maulana Abdur Rahman and Maulana Abdullah were also killed, according to the official.
Four of the people killed by the strike, which occurred in the northwest Hangu district of the Khyber Pakhtunkhwa, were not Pakistani nationals, the source added.
The Pakistani Taliban has been blamed for the deaths of at least 40,000 civilians and 5,000 troops during its decade-long insurgency against the country's government.
Thursday's attack was the first drone strike in the country since Pakistani Taliban chief Hakimullah Mehsud was killed on November 1.
The Haqqanis established themselves as key players in the region during the war against the Soviet Union after the 1979 invasion of Afghanistan. They have been proscribed by the U.S. as a terrorist organisation.
The group's chief financier, Nasiruddin Haqqani, was shot dead in Islamabad on November 11.
“The Haqqani network has been fighting for 35 years,” Dr. Lieven said. "Anyone who thinks these people can be deterred by death has not been paying attention. The idea that they might surrender is fatuous.
“This will undoubtedly incline the Haqqani network still further against any peace talks with the American and Afghan governments and will give them an even stronger motive to disrupt next year’s elections,” he added.
NBC News' Henry Austin and Reuters contributed to this report.