<p>WASHINGTON (AP) - Officers along the U.S.-Canadian border and on New York City's streets are being extra vigilant for five men of Middle Eastern origin who may have crossed the border into the United States on Christmas Eve.</p>
<p>Officials have not ruled out a connection to a terrorist plot or cell, but they could not confirm a link, either. White House spokesman Scott McClellan said Monday the intelligence that triggered the search came from an anti-terrorism investigation.</p>