At least 73 people were killed in Pakistan's province of Balochistan when armed men attacked police stations, railway lines and highways, and security forces launched retaliatory operations.
The assaults were the most widespread in years linked to a decades-long insurgency to win secession of the resource-rich southwestern province, home to major China-led projects such as a port and a gold and copper mine.
"These attacks are a well thought-out plan to create anarchy in Pakistan," Interior Minister Mohsin Naqvi said in a statement.
Pakistan's military said 14 soldiers and police and 21 attackers were killed in fighting after the largest of the attacks, which targeted buses and trucks on a major highway.
Balochistan's chief minister said 38 civilians were also killed. Local officials said 23 of them were killed in the roadside attack after gunmen checked passengers' IDs before shooting many of them and torching vehicles.
"People were taken off buses and killed in front of their families," Chief Minister Sarfraz Bugti said in a televised press conference.
Rail traffic with Quetta was suspended following blasts on a rail bridge linking the provincial capital to the rest of Pakistan. The armed men also struck a rail link to neighbouring Iran, railways official Muhammad Kashif said.
Police said they had found six as yet unidentified bodies near the site of the attack on the railway bridge.
Police and security stations were targeted in Balochistan, Pakistan's largest province by area but least populated, killing at least 10 people in one attack.
The Baloch Liberation Army (BLA) took responsibility for the operation they called "Haruf" or "dark windy storm". In a statement to journalists they claimed more attacks over the last day that have not yet been confirmed by authorities.
The group said four suicide bombers, including a woman from the southern port district of Gwadar, had been involved in an attack on the Bela paramilitary base. Pakistani authorities did not confirm this, but the provincial chief minister said three people had been killed at the base.
The BLA is the biggest of several ethnic insurgent groups battling the central government, saying it unfairly exploits gas and mineral resources in the province, where poverty is rife. It wants the expulsion of China and independence for Balochistan.
Monday was the anniversary of the death of Baloch nationalist leader Akbar Bugti, who was killed by Pakistan's security forces in 2006.
Prime Minister Shehbaz Sharif vowed that security forces would retaliate and bring those responsible to justice.
Bugti, the chief minister, said more intelligence-based operations would be launched and he hinted at curtailing mobile data services to stop attackers' coordination.
General Li Qiaoming, commander of China's People's Liberation Army Ground Forces, and Pakistan's army chief Asim Munir met on Monday, though a Pakistani military statement released after the meeting made no mention of the attacks.