A blast ripped through a congregation of worshippers during Friday prayers at a mosque in Pakistan's northwestern tribal region of Khyber today, killing at least 40 people, government officials said.
Local administrator Fazal Khan says there's some evidence it was a suicide attack.
Some 300 people were at the mosque for prayers during the holy month of Ramadan when the bomb exploded in Ghundi village of Khyber tribal region.
Pakistan's tribal belt is a hotbed of Islamist militant activity, as well as sectarian rivalry.
No group claimed responsibility for the bombing, but the Taliban and other insurgents have attacked scores of targets in the area, which lies along the Afghan border.
Pakistan has seen a wave of violence in recent years in which thousands of people have been killed.
There have been several bomb attacks since US special forces killed al-Qaeda chief Osama bin Laden in a secret raid in a Pakistani town in May.
Al-Qaeda-linked militants have vowed to avenge bin Laden's death.
Agencies