The BBC said an attack on a Pakistani military convoy near the nation's northwest border killed 11 soldiers, while 26 people were killed a short time later when a bomb exploded in the city of Dera Ismail Khan.
A similar convoy attack occurred Saturday north of the town of Miranshah. That incident left 24 dead and 30 people injured.
Sunday's deadly attacks came as pro-Taliban militants operating in the North Waziristan region rescinded a peace treaty they had with the government. The militants accused the government of violating the peace agreement through recent actions.
Government troops have been deployed throughout the area recently in response to the militant siege at Islamabad's Red Mosque last week.
The BBC said Sunday's attack on a police deployment center in Dera Ismail Khan left more than 30 people injured, while 40 others were injured during an attack by the town of Matta.