Unclear why they were there as yet; according to the U.S. embassy in Islamabad they were helping train the Pakistanis in counterinsurgency. But there’s this:
The American soldiers, who may have been part of a training unit, were en route to inspect a proposed site for small-scale development projects that were to be undertaken by the Frontier Corps, a paramilitary force that the American Army has been training, a senior official in the North-West Frontier Province said. …
That American soldiers were involved in development assistance had not been previously known.
Given the sensitivities in Pakistan to a U.S. troop presence, how smart is it to be using soldiers for development work and not, say, civilian development experts? Of course, that’s assuming the embassy’s story is true.