Last week's attack killed 149 people -- most of them children of the local army personnel. The Taliban claimed it was a revenge for the army action against its families.
"Our hearts are bursting with pain and grief over this incident," Osama Mehmood, spokesman for Al-Qaeda's South Asia chapter, said in a four-page statement e-mailed to the media. (Silent Classes, Bloody Notebooks: Day After the Pakistan School Massacre)
Pakistan has described the bloody rampage as its own "mini 9/11", saying it was a game changer in its fight against terror. The outrage has apparently eroded the sympathy for militants in a country where many people have long been suspicious of the US-led "war on terror". There is pressure on the army to intensify the offensive launched this year on terror havens along the Afghan border. (Pakistan: 59 Militants Killed After School Massacre)
In September, Al-Qaeda chief Ayman al-Zawahri had announced the creation of the new South Asia chapter in September to "wage jihad" in Myanmar, Bangladesh and India.
"The guns that we have taken up against Allah's enemy America and its pet rulers and slave army should not be aimed towards children, women and our Muslim people," he added.
The Afghan Taliban, who are loosely affiliated with Tehreek-e-Taliban Pakistan, have also condemned the attack, saying killing innocent children was against Islam. (Peshawar Attack Not Taliban's First on a School)