Pakistan's military said in a statement sent by text message that 15 security personnel were also killed during clearance operations while militants targeted civilians in several areas, killing at least 18 people, including women and children.
The attacks were carried out a day after Pakistan's military said it killed 41 militants in separate raids in Balochistan, which borders Iran and Afghanistan and has faced a decades-long separatist insurgency.
The banned separatist group Baloch Liberation Army (BLA) claimed responsibility for Saturday's attacks, saying it had launched them simultaneously across the province.
The BLA said it had killed 84 Pakistani security personnel and that the ongoing operation had continued for 15 hours.
The military's media wing, ISPR, said the attacks were carried out by Indian-sponsored militants and that security forces had thwarted attempts to seize control of any city or strategic installation.
"Intelligence reports have unequivocally confirmed that the attacks were orchestrated and directed by terrorist ringleaders operating from outside Pakistan, who were in direct communication with the terrorists throughout the incident," the statement said.
It said the attacks were launched across Quetta, Mastung, Noshki, Dalbandin, Kharan, Panjgur, Tump, Gwadar and Pasni.
Pakistani Interior Minister Mohsin Naqvi condemned the attacks and praised security forces for repelling them, saying in a statement that they had killed dozens of militants.
Security officials said armed men launched attacks in several urban areas, including the provincial capital Quetta and the port city of Gwadar, prompting operations by the army, police and counterterrorism units.
Hospitals were placed on emergency footing in some districts, officials said.
In Gwadar, militants attacked a camp accommodating migrant workers, killing 11 people, Atta-ur-Rehman, a senior police officer said.
Those killed included five men, three women and three children.
Security forces killed six militants in Gwadar after responding to the attack, he said.
Officials said the situation was critical in Noshki, a district of Balochistan, after militants abducted the area's top civil administrator.
He said in a social media video that he was in the custody of the militants.
Reuters could not independently verify the video.
Armed men briefly blocked roads in parts of Quetta and a blast was heard near a high-security area, authorities said, though they later said the situation had been brought under control.
Security officials said in text messages that forces had responded effectively to the attacks and that clearance operations were still underway.
Balochistan is Pakistan's largest but poorest province and has faced a decades-long insurgency by ethnic Baloch militant groups.
Pakistan says the violence is backed by foreign actors, a charge denied by India.
