RNA - The blast occurred during Friday prayers in a tribal area bordering Afghanistan, Naveed Akbar, the deputy administrator of Mohmand agency, said.
"The suicide bomber was in crowded mosque,” he added, saying, it was a “huge blast.”
A second regional official confirmed the bombing in the village of Payee Khan, in the troubled Mohmand region of the lawless Federally Administered Tribal Areas (FATA).
Shaukat Khan, another official in the northwestern FATA region, said at least 24 people were wounded.
"Many people were gathered inside the mosque where a suicide bomber blew himself up," he said.
There was no immediate claim of responsibility but pro-Taliban militants are usually blamed for such attacks.
Thousands of people have been killed over the past decade as a result of the surge in violence in Pakistan.
Pro-Taliban elements killed over 150 people, most of them children, in an armed assault on a school in the northwestern city of Peshawar in December 2014.
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