Pakistan is engaged in a military offensive in Buner district
Pakistan's army has accused Taleban militants of "reportedly" holding 2,000 villagers as human shields to stop an offensive in the north-west.
The military wants to clear insurgents from Pir Baba, an important religious shrine in Buner district, about 100km (62 miles) from the capital, Islamabad.
A BBC correspondent in Islamabad says it is not possible to verify the claim.
The military has been engaged in an offensive to remove insurgents from the Lower Dir and Buner regions.
The Pakistani government is trying to stop the Taleban extending its influence beyond the Swat Valley, an area which they largely control.
When the Taleban seized control of Buner last month, Pir Baba was one of the first places they took control of.
They still hold it, despite the army deploying tanks, helicopter gunships and warplanes to the district to defeat them.
The military says its operations elsewhere in the district are progressing well.
In a statement released on Monday, it said security forces had attacked Taleban positions in Buner and had killed seven militants, including an important commander.
Security forces have been battling Taleban militants in four of Buner's six sub-districts.
Militants are in control of the remaining two districts.
Buner resident Nasir Khan told Reuters news agency by phone: "There's been heavy firing going on since morning. It is very scary. Troops are using heavy artillery and gunships."
The BBC's Syed Shoaib Hassan, in Islamabad, says that although security forces appear to have the upper hand, the militants are resisting fiercely and it may be sometime before the forces can take complete control of Buner.
Their commanders had originally hoped to do this within a week.