The offensive was in Bara Tehsil,
the Pashtun part of the Khyber Agency. The 2,500 people who have been taken into custody represents a significant portion of the entire population of the sparsely populated area.
The area is a hotbed of militancy
and is the birthplace of Lashkar-e-Islam
an active group of militants. In April of 2008, the leader of the group claimed that there were over 180,000 volunteers in Khyber Agency. The group often comes into conflict with the Frontier Corps when they launch offensives in the area. Many civilian casualties are reported.
Khyber and the remainder of the FATA (Federally Administered Tribal Areas) are not given the status of provinces within Pakistan. The central government is often in conflict with tribes in the area. When tribes are regarded as insufficiently loyal to the central government, offensives are often ordered. The Frontier Corps
are specifically designed to fight in these areas. They are organized as a militia but commanded by the Pakistan Army and federally administered. The group dates back to colonial times in the early part of the twentieth century.
The entire force number about 80,000 troops. The FC help out local law enforcement personnel, but they are now used in Balochistan and also the FATA to mount military operations against insurgents.
U.S. government military and intelligence experts see the FC as the best units to use against local militant groups, since they are recruited locally and understand the local languages and culture. Much of the U.S. $7 billion in military aid provided Pakistan from 2002 to 2007 was used to equip and train the FC, since they are on the front line against militants in the tribal areas. The FC are, in effect, proxy fighters in the U.S. war on terror.
Should relations worsen with Pakistan and U.S. aid be cut off, you can expect there may be blow-back in which the FC troops cast their lot with the militants when they are no longer paid to fight them.