Four children were injured when rockets fired from Afghan territory landed in Pakistan's North Waziristan tribal region on Monday, local tribesmen said.
The injured were taken to the main hospital in Miranshah, the headquarters of North Waziristan Agency, they said.
One child was in a critical condition, doctors said.
Tribesmen said scores of rockets landed in Bang Dar border village and some hit houses.
It could not immediately be ascertained whether NATO or Afghan forces fired the rockets.
Pakistani and Afghan officials have angrily traded charges about shelling in each other's territory over the past few days, triggering a diplomatic row between the two countries.
The governments in both countries summoned ambassadors to the foreign ministries to lodge formal protest.
Islamabad says armed militants from Afghanistan entered Pakistani areas and launched five attacks in a month on border checkpoints and villages, killing nearly 40 soldiers and injuring 80 others.
Afghan authorities say Pakistani forces have fired hundreds of rockets and artillery shells into Afghanistan’s eastern Kunar and Nangrahar provinces, killing dozens of people, including women and children.
Tension along the border has increased at a time when Pakistan and Afghanistan have formed a joint peace and reconciliation commission to work jointly to bring the Afghan Taliban to the negotiating table.