US STOCKS-Wall St tumbles on Ukraine concerns; energy weighs
* Market sells off in afternoon after Ukraine-related headlines
* Treasury yields fall, gold ticks higher
* Indexes off: Dow 1.0 pct, S&P 1.1 pct, Nasdaq 0.9 pct (Updates prices, comment)
By Rodrigo Campos
NEW YORK, Aug 5 (Reuters) - U.S. stocks fell on Tuesday in broad selling led by energy shares as crude prices fell and as traders cited concern about possible escalation of military action in eastern Ukraine.
Selling accelerated in the afternoon after a Bloomberg report that cited the Polish Foreign Minister and said Russian units were poised to pressure or invade Ukraine.
"The market was vulnerable to begin with, with a number of commentators questioning Monday's rebound," said Quincy Krosby, market strategist at Prudential Financial in Newark, New Jersey.
She cited the concerns over Ukraine, saying "volume is very light and the market can be skewed in any direction with a headline crossing the wires."
Spot gold prices turned higher after trading down for most of the session. Benchmark U.S. Treasury yields hit session lows. Continuación...