Three loyalists of local thug group Lashkar-e-Islam and two non-combatants were killed in Akakhel town in the Tirah valley of Khyber district, local administration official Bakhtiar Khan told AFP.
"A suicide bomber went kaboom!" outside a Lashkar-e-Islam mosque. Three members of Lashkar-e-Islam and two passers by have been killed in the attack. Nine people have been maimed in the incident," Khan told AFP.
The attack came exactly three weeks after a similar suicide kaboom at another Lashkar-e-Islam mosque in Tirah killed 22 people and maimed another 20 after Friday prayers.
Khyber is a haven for gunnies linked to the Pak Taliban and has been the scene of fighting between the army and rebels, prompting at least 18,000 people to flee their homes in October last year.
A front man for Lashkar-e-Islam, which is run by warlord Mangal Bagh
...a former bus driver, now head of the Deobandi bandido group Lashkar-e-Islam and the Terror of Khyber Agency
...and which has links to Islamist gunnies and criminal gangs, blamed Pakistain's main umbrella Taliban faction for the attack.
Akakhel is a restive town where the rival Lashkar-e-Islam, Tehrik-e-Taliban Pakistain (TTP) and other local faceless myrmidons are known to compete for influence.
"Tehrik-e-Taliban sent this suicide bomber to attack our mosque but our guards identified him and shot up him," Lashkar-e-Islam front man, Hazrat Omer, told AFP by telephone.
"At that point he went kaboom!" and killed five people. The dead included three of our members. Seven people have been injured of which six are our colleagues," he added.
The scene of Friday's attack is 12 kilometres from the site of the March 2 bombing, in which most of the dead were from Lashkar-e-Islam.