Pakistan’s Taliban has struck again. The group Jamaat-e-Ahrar has claimed responsibility for a suicide bombing on Sunday in a park in Lahore crowded with families, including many Christians enjoying an Easter outing. The bomber set off his explosives near a swing set, killing at least 69 people and injuring more than 300 others.

A spokesman for the Taliban group said the attack had two objectives: to kill Christians and to “give a message to government that it cannot deter us even in their stronghold, Lahore.” Lahore, the capital of Punjab Province, is the hometown of Prime Minister Nawaz Sharif. Mr. Sharif’s brother, Shahbaz Sharif, is the province’s chief minister.

The attack was meant to expose as hollow Mr. Sharif’s claims — intended to reassure foreign investors and Pakistani citizens — that he has the Taliban on the run. Clearly it is not on the run — in part because a succession of Pakistani governments and the military have cynically used terrorist groups for their own purposes, encouraging them to act as proxy fighters against India.

Murdering women and children at play is all too typical of the Taliban’s atrocities. Pakistan’s Taliban has long targeted students, including the 2012 assassination attempt on Malala Yousafzai, an activist for girls’ education; the December 2014 massacre of 150 students and teachers at an army-run school in Peshawar; and the attack on students at Bacha Khan University, also near Peshawar, in January.