After the Sept. 11, 2001, attacks on the United States, the tribal areas — particularly South Waziristan, where Mr. Mehsud was from, and North Waziristan — became a front line of the war on terrorism, as Al Qaeda and other groups took refuge there. Pashtuns in the tribal areas suffered both from militant attacks and from crackdowns by the army, and those who fled to other parts of Pakistan — like Karachi, in Mr. Mehsud’s case — say persecution followed them.
“Thousands of young Pashtun boys have disappeared in the last decade and a half, picked up from their homes and universities and streets in the name of curbing militancy,” said Farhad Ali, the 24-year-old vice chairman of the Fata Youth Jirga, one of the organizations leading the Islamabad protests. “We want all these young men to be produced before a court of law and concrete evidence presented that they have committed any crime.”
“This is one of our major demands: Stop this stereotyping of Pashtuns as militants,” Mr. Ali said. “Stop imposing curfew in our areas every time there is any untoward event in another part of the country. Let us live in peace, please.”
The demonstrators, who have set up tents outside the National Press Club in Islamabad, are also demanding the arrest of Rao Anwar, a Karachi police commander who has been accused of killing Mr. Mehsud and who is now on the run.
They also say they want the army to clear land mines from the tribal areas, particularly the South Waziristan district. Mr. Ali said that since 2009, more than 35 people had been killed by land mines in South Waziristan.
“I wanted to do something with my life, I wanted to become someone, but look at me,” said Islam Zeb, from South Waziristan, who took part in the Islamabad protest. Mr. Zeb said he had been blinded in a land mine blast that cost his brother his hand.
“If a soldier is wounded in a land mine explosion, entire families are arrested, people disappear without a trace,” Mr. Zeb added.
The Pakistani Army’s media wing denied that the army had ever laid mines in the tribal areas, saying that militants had done so. But it said that the army would send 10 demining teams to South Waziristan immediately.
Other officials were also quick to assure the demonstrators that they had been heard. Tariq Fazal Chaudhry, a government minister who met with protest leaders, said the government fully supported their demands. But he declined to say when they would be met.
Manan Ahmed Asif, a professor of history at Columbia University, called the tribal areas “a geography outside the laws of the nation,” where both militant groups and the army had found that “violence could be meted out with little regard to its inhabitants.”
At least 70 percent of the region’s five million people live in poverty, the literacy rate is just 10 percent for women and 36 percent for men, and the infant mortality rate is the nation’s highest. For years, Pakistani militants have used the lawless area to initiate assaults against Pakistan’s government and against United States-led forces in Afghanistan.
Since 2001, the Pakistani military has launched 10 operations against militant strongholds in the region, most recently in 2013 in North Waziristan. The offensives have displaced almost two million people, according to figures from the United Nations refugee agency and the Geneva-based Internal Displacement Monitoring Center, as homes, schools and hospitals have been turned into hide-outs by militants and meager civic amenities have been destroyed.
The Pakistani Army says it is now spending millions to repatriate displaced people, rebuild infrastructure and earn residents’ good will. But many residents still view the soldiers as occupiers, and militants continue to pose a threat.
Parliament is considering a proposal to merge the war-torn and neglected tribal areas with the adjoining province of Khyber-Pakhtunkhwa. That would allow the people in the tribal areas to become full citizens of Pakistan for the first time. But the plan has become a divisive issue among those favoring reform, with some political parties opposing a merger and calling for the tribal areas to become a separate province instead.
Simbal Khan, a security analyst and nonresident fellow at a think tank, the Center for International Strategic Studies, in Islamabad, said she was skeptical that the protests would lead to real change for Pashtuns.
“All this movement you see, it is pre-election mobilization,” Ms. Khan said, referring to national elections scheduled for July.
“It doesn’t portend to become a genuine Pashtun uprising,” she added. “Political parties and other groups want to pick up issues that resonate with the public, and this march provides them a platform. This is just politicking.”