It was unclear whether the explosion was caused by a suicide bomber or an improvised explosive device, local government official Mudassir Bangash told Al Jazeera. "Reports are still coming in, nothing is confirmed yet," Bangash told Al Jazeera by telephone.

Abbas Khan, the assistant commissioner of the district, told the Reuters news agency that a suicide bomber had driven his motorcycle into a crowd attending a festival and market that attracts people from various religious communities.

Earlier, the AFP news agency, citing a police official, reported that the blast was caused by an improvised explosive device placed in a carton of vegetables at the market in Khyber Pakhtunkhwa province.