Several people were also wounded in the blast in Khyber Pakhtunkhwa province's Hangu district, senior government official Khalid Khan Omarzai said.
Elsewhere in the region, a missile fired from a U.S. drone destroyed a vehicle in the Mir Ali town of North Waziristan, killing at least four suspected militants, Pakistani intelligence officials said. The identity of those killed was not immediately known.
The officials spoke on condition of anonymity because they were not authorized to speak to the media.
The suicide attack in Hangu comes a day after the start of the holy month of Muharram, which is especially important for Shiites, but has been marred by bombings.
Hangu has been the site of attacks in the past by extremist Sunni militant groups targeting Shiites. The town is effectively segregated between the two Muslim sects, with each having their own markets, hospitals and schools.
Earlier this week, a bomb attack in nearby Kohat town killed 15 people.
Pakistan's tribal regions are home to thousands of militants staging or supporting attacks on American troops in neighboring Afghanistan. It also houses al-Qaida leaders and operatives from around the world plotting attacks on the West.
The United States is squeezing the insurgents with missiles fired from unmanned drones. The frequency of such attacks has surged under the Obama administration.
Room view Peshawar
© Kieron Nelson 2007 "Vanishing Cultures Photography"