KARACHI, Pakistan - When vast crowds paid their last respects to Benazir Bhutto before her burial, angry mourners from her native Sindh province chanted separatist slogans: "We don't want to be part of Pakistan!"
Although Bhutto, a two-time prime minister and leader of the country's biggest party, was an icon of Pakistani nationalism, her violent death in the heart of Punjab province has laid bare bitter regional rivalries in a nation carved out of the subcontinent after British colonial rule ended 60 years ago.
Many among the ethnically distinct peoples in Pakistan's three minority provinces harbor deep resentment toward the most populous province of Punjab, which dominates the government, military and allocation of federal resources.
Aside from bubbling tensions in Sindh, Pakistan is grappling with outright separatist rebellion in the deserts of Baluchistan, as well as escalating militancy in the North West Frontier province near Afghanistan.
A breakup of the federation is unlikely, but Bhutto's slaying touched a particularly raw nerve as she was the third Pakistani prime minister from Sindh to have died a violent death. The Islamic nation's first premier, Liaquat Ali Khan, was shot dead in 1951, and her father Zulfiqar Ali Bhutto was executed in 1979 for allegedly conspiring to kill a rival.
All three died in Rawalpindi, the garrison city of the Punjabi-dominated army -- a fact not lost on the thousands who gathered for Benazir's funeral at her ancestral home, where she was buried beside her father. Bhutto herself had also claimed elements of the Punjabi-dominated ruling party were seeking to kill her, claims that it denied.
"After all this they are asking us to calm down ... why should we?" asked Pir Bakhsh Jhakrani, a messenger in his 50s living in Larkana, the Bhutto clan's stronghold. "Those ruling the country should stop conspiring against Sindh if they want to keep the country intact."
Bhutto's death on Dec. 27 sparked the worst unrest in Pakistan in years -- most of it focused in Sindh where ethnic nationalists have been calling for more power since the rule of Islamist military dictator Gen. Zia ul-Haq, under whose rule Zulfiqar Ali Bhutto was convicted and killed.
"We will only stay in Pakistan which must be a democratic, secular Pakistan where we are an equal partner in state affairs," said Qader Magsi, chairman of the Sindh Taraqi Pasand Party, or Sindh Progressive Party.
Secessionist sentiments remain strongest in neighboring Baluchistan, Pakistan's biggest and poorest province, where the army is deployed to fight ethnic rebels who often attack energy infrastructure -- much of the natural gas piped into homes in Punjab originates here.
Sardar Attaullah Mengal, chief of Baluchistan National Party, alleged the rebels were motivated by torture and abduction of young men by government forces.
"Baluchistan has been made a colony of Punjab and Baluchis will never accept living in Pakistan as a colony," said Mengal, a former chief minister of the province. "Punjab will have to give rights to Baluchistan and other provinces on the basis of equality if they have to live in Pakistan. Any other status lesser than that is not acceptable."
Ethnic Pashtuns who live in areas bordering Afghanistan where they are the majority -- mostly in the volatile northwest -- also said the political balance must shift.
"Pakistan cannot run the way they are running the federation: that Pakistan is Punjab and Punjab is Pakistan," said Asfandyar Wali Khan, president of the Awami National Party, Pakistan's largest Pashtun nationalist group.
Still, few citizens even in the three minority provinces want outright separation from Pakistan. Memories of the country's last painful division are still fresh.
It was under the presidency of Bhutto's father that eastern Pakistan splintered off into today's Bangladesh in the early 1970s after a humiliating military defeat by India. His charismatic rule during that time spawned the political legacy that carried over to his daughter.
Quetta photo shop owner Asadullah Baluch, 28, said his people just want more autonomy.
"If Baluchistan is given control over its resources and the province is allowed to participate in national affairs, and the province is given representation in the establishment and foreign services, this conflict will end," he said.
Rasul Bakhsh Rais, a political scientist at the Lahore University of Management Sciences, said Islamic militancy rather than ethnic movements posed the biggest threat to the federation.
Pro-Taliban militants have grabbed control of lawless, semiautonomous tribal regions such as South and North Waziristan, where the U.S. fears al Qaeda is regrouping. They have also challenged the government's authority further inland in the North West Frontier Province.
"Ethnic nationalists can be negotiated with and many of their demands for sharing power and allocating resources are legitimate. These can be settled," Rais said. "But the Taliban are using force to threaten the border regions of Pakistan."
