Serbian military vehicles drive near the border with Kosovo as tensions in the region rise amid recent violence. The killing of a Kosovo police officer and an ensuing gun battle at a monastery brought years of distrust and bitterness to the surface -- as a war of words between Serbia and Pristina's governments, competing days of mourning, and calls for sanctions marred already fractious relations. The United States on Friday warned of "a large Serbian military deployment along the border with Kosovo" and called on "Serbia to withdraw those forces from the border". IMAGES from near the Serbia-Kosovo border