A bomb ripped through a passenger van in a restive area of Pakistan's Khyber region near the border with Afghanistan on Wednesday, killing at least six people, officials reportedly said.
According to Agence France-Presse, the van was carrying 15 men from Khurrakai village to Jamrud, the main town in Khyber district.
AFP quoted Shakeel Khan Umarzai, a senior administration official, as saying: "The passengers were going to town for shopping. So far we can confirm the death of six people while nine others are injured."
He added: "It is unclear that the blast was caused by an IED or a planted bomb in the van but explosives were used."
The Associated Press quoted Iqbal Khan, a Pakistani official as saying the blast was from a bomb was planted inside the van, although it was unclear whether it was a remote-controlled or a timed device.
Khyber is a district in Pakistan's semi-autonomous tribal belt, AFP wrote, adding that Washington has dubbed it the most dangerous place on Earth and the global headquarters of Al Qaeda.
More from GlobalPost: Torture accusations surface in Pakistan’s violent tribal regions
The terrorist group, along with Taliban militants, have carved out strongholds from where they plot attacks on targets in the West, as well as on Pakistanis and Afghans who don't support them.
According to the AP, Islamist militants have carried out scores of bombings in northwest Pakistan in recent years, often targeting civilians or those from tribes who do not support them.
More from GlobalPost: Khyber Agency: suicide attack kills 5 in Pakistan's volatile tribal region
The UN refugee agency said Friday that more than 100,000 people, mostly women and children, have fled the fighting in Khyber since Jan. 20.
“An estimated 101,160 people, mostly women and children, have become displaced since Jan. 20 when government troops began security operations against militant groups in the Khyber” tribal district, the Pakistan Observer quoted the UNHCR as saying in a statement.
Many families were fleeing to to Jalozai camp near the western Pakistan city of Peshawar.
More from GlobalPost: Your body parts, made to order