The bombing took place in the city of Mardan, outside the regional office of the National Database and Registration Authority, or NADRA, which issues identity cards, according to senior police officer Saeed Khan Wazir.
Wazir told The Associated Press that some of the wounded were in critical condition at a hospital in the nearby city of Peshawar.
"A gunman opened fire and killed a guard upon being asked to stop for checking. Then he exploded his suicide jacket," he said. Wazir said if the attacker had managed to enter the government office, he might have killed many more people.
Mohammad Qasim told The Associated Press from his hospital bed that he went to the office to receive his national identity card, which is issued at age 18.
"I was in a very happy mood today. I told my family and friends that I would receive my national identity card, but I didn't know that I would become the target of a bombing," said Qasim, who had bandages on both legs.
Shortly after the attack, a spokesman for the militant Jamaat-ul-Ahrar group claimed responsibility for the bombing, calling it a "noble act to punish NADRA because it extends support to security forces." The spokesman, Ahsanullah Ahsan, spoke to the AP by phone from an undisclosed location.
Jamaat-ul-Ahrar split from the Pakistani Taliban two years ago.
Prime Minister Nawaz Sharif condemned the bombing and instructed authorities to provide the best possible treatment for the wounded.
Mardan is about 50 kilometers (30 miles) northwest of Peshawar, the capital of Khyber Pakhtunkhwa province, which borders Afghanistan and the North Waziristan tribal region.
In Washington, State Department spokesman Mark Toner told reporters the U.S. strongly condemns the attacks and extends its condolences to the families of the victims.
"The United States remains committed to the people of Pakistan and to the Pakistan government's efforts to fight terrorism," Toner said.
Pakistani forces have been carrying out a major operation against the Taliban and other militants in North Waziristan since 2014. Earlier this month, the military claimed "phenomenal successes" in the war and said it has killed around 3,500 insurgents since launching the operation.
But attacks have been rampant in Khyber Pakhtunkhwa, and in December 2014, militants killed 148 people, mainly children, in an attack on an army-run school in Peshawar. The Taliban later claimed responsibility for the school attack.
Also Tuesday, Pakistan executed four convicted militants for involvement in acts of terrorism, according to two officials. The officials spoke on condition of anonymity as they were not authorized to speak to media. Since the school attack, Pakistan has executed 330 people, most of them convicted criminals, not militants.
(AP)
Pakistani security officials examine the site of suicide attack in
Mardan, Pakistan, Tuesday, Dec. 29, 2015. A suicide bomber blew himself
up outside a government office in a northwestern Pakistani city on
Tuesday, killing more than a dozen and wounding tens. A breakaway
Taliban group quickly claimed responsibility for the attack.
People comfort a man who lost a family member in a suicide attack in
Mardan, Pakistan, Tuesday, Dec. 29, 2015. A suicide bomber blew himself
up outside a government office in a northwestern Pakistani city on
Tuesday, killing more than a dozen people and wounding tens. A breakaway
Taliban group quickly claimed responsibility for the attack.
A Pakistani man injured from a suicide attack, waits for ambulance in
Mardan, Pakistan, Tuesday, Dec. 29, 2015. A suicide bomber blew himself
up outside a government office in a northwestern Pakistani city on
Tuesday, killing more than a dozen people and wounding tens. A breakaway
Taliban group quickly claimed responsibility for the attack.
Pakistani security officials examine the site of a suicide attack in
Mardan, Pakistan, Tuesday, Dec. 29, 2015. A suicide bomber blew himself
up outside a government office in a northwestern Pakistani city on
Tuesday, killing more than a dozen people and wounding tens. A breakaway
Taliban group quickly claimed responsibility for the attack.
A Pakistani security official collects evidence at the site of a suicide
attack in Mardan, Pakistan, Tuesday, Dec. 29, 2015. A suicide bomber
blew himself up outside a government office in a northwestern Pakistani
city on Tuesday, killing more than a dozen people and wounding tens. A
breakaway Taliban group quickly claimed responsibility for the attack.
People comfort a man lost his family member in a suicide attack in
Mardan, Pakistan, Tuesday, Dec. 29, 2015. A suicide bomber blew himself
up outside a government office in a northwestern Pakistani city on
Tuesday, killing more than a dozen people and wounding tens. A breakaway
Taliban group quickly claimed responsibility for the attack.
A Pakistani child injured in a suicide attack admits at a local hospital
in Mardan, Pakistan, Tuesday, Dec. 29, 2015. A suicide bomber blew
himself up outside a government office in a northwestern Pakistani city
on Tuesday, killing more than a dozen people and wounding tens. A
breakaway Taliban group quickly claimed responsibility for the attack.