At least 14 people have been killed and 35 wounded in a explosion in a remote district in northwestern Pakistan, according to police.
"We don't know whether it was a bomb blast or somebody lobbed hand grenades into the mosque or there was some other cause of the explosion," Fida Hasan Shah, police chief of Dir district told reporters. He said the death toll could rise.
Earlier, Pakistan's army chief said Pakistan would not allow foreign troops to conduct operations on its soil after a cross-border incursion by US commandos.
The strongly-worded statement by General Ashfaq Kayani coincided with comments by the US Chairman of the Joint Chiefs of Staff, Admiral Mike Mullen, that a "more comprehensive strategy" was being formed to combat the threat from the Taliban and al Qaeda in the region.
General Kayani, who met Mr Mullen and other senior U.S. commanders on an aircraft carrier in the Indian Ocean on Aug. 28, delivered a clear message that foreign forces would not be tolerated on Pakistani territory, without directly referring to Mr Mullen's comments.
"The sovereignty and territorial integrity of the country will be defended at all cost and no external force is allowed to conduct operations ... inside Pakistan," a military statement quoted General Kayani as saying.
Helicopter-borne US commandos carried out a ground assault in Pakistan's South Waziristan, a sanctuary for al Qaeda operatives, last week, the first known incursion into Pakistan by US troops since the 2001 invasion of Afghanistan, killing 20 people, including women and children.
Reuters