Home Minister Rajnath Singh said the attack in the northwestern city of Peshawar exposed the “real face of terrorism”.
“I strongly condemn the terrorist attack on a school at Peshawar,” he tweeted.
“This dastardly & inhuman attack exposes the real face of terrorism. My heart goes out to the families of those children who got killed by the terrorists in Peshawar.”
Strongly condemn the cowardly terrorist attack at a school in Peshawar.
— Narendra Modi (@narendramodi) December 16, 2014
Witnesses described how gunmen went from classroom to classroom, shooting children, after a huge blast shook the Army Public School.
The Tehreek-e-Taliban Pakistan (TTP) claimed responsibility for the attack as retaliation for a major military offensive in the region, saying militants had been ordered to shoot older students.
I strongly condemn the terrorist attack on a school at Peshwar(Pakistan). This dastardly & inhuman attack exposes the real face of terrorism
— Rajnath Singh (@BJPRajnathSingh) December 16, 2014
India has repeatedly urged Pakistan to rein in militant groups operating on its soil.
India and Pakistan have fought three wars since independence in 1947, and deadly attacks on Mumbai by Pakistan-based militants dealt a blow to tentative peace talks in 2008.
Washington has also pressed Islamabad to wipe out sanctuaries in North Waziristan, which militants have used to launch attacks on NATO forces in Afghanistan.