<p>WASHINGTON (Reuters) - U.S. intelligence agencies provided advanced warning to Russia about a major terrorist plot in St. Petersburg, allowing Moscow to thwart an attack that could have killed &#8220;large numbers of people,&#8221; the White House said on Sunday.</p> 
<p>&#8220;President Vladimir V. Putin of Russia called President Donald J. Trump today to thank him for the advanced warning the United States intelligence agencies provided to Russia concerning a major terror plot in Saint Petersburg, Russia,&#8221; the White House said in a statement.</p>
U.S. tip-off helped Russia thwart 'major' terrorist plot: White House