* Ten-, 30-year yields hit lowest in over a year
* Renewed Russia-Ukraine tensions drive safety bid
* Weak U.S. factory, consumer sentiment data weigh too (Updates prices, adds comments)
By Sam Forgione
NEW YORK, Aug 15 U.S. benchmark and long-term Treasuries yields fell to their lowest in over a year on Friday after rising tension between Russia and Ukraine drove safe-haven bids for the debt.
Ukraine's President Petro Poroshenko said artillery had destroyed a "significant" part of a Russian armored column that had crossed into Ukraine during the night.
Russia, meanwhile, accused Ukraine of attempting to disrupt a Russian humanitarian aid mission to eastern Ukraine and called for a ceasefire to allow for the deliveries.
"When a cold war starts to turn hot, everybody becomes more worried about where it could lead," said Aaron Kohli, an interest rate strategist at BNP Paribas in New York. "This is a really rich market but people are getting really scared of shorting it with this geopolitical backdrop."
While the news about Ukraine drove much of the plunge in Treasuries yields, they had started to fall earlier on weak U.S. economic data, including cooling factory activity in New York state and a dip in consumer sentiment.
The New York Federal Reserve said its 'Empire State' general business conditions index fell to 14.69 this month from 25.60 in July. A reading above zero indicates expansion.
The Thomson Reuters/University of Michigan's preliminary August reading on the overall index on consumer sentiment came in at 79.2, down from a final reading of 81.8 the month before and its lowest since November.
Benchmark 10-year U.S. Treasury notes were last up 18/32 in price to yield 2.33 percent. The yield earlier hit a session low of 2.30 percent, its lowest since June 2013. Bond yields move inversely to prices.
Prices on 30-year Treasury bonds were last up 1-13/32 to yield 3.13 percent. The yield earlier hit a session low of 3.11 percent, its lowest since May 2013.
"If you see a continued escalation of what's going on in Ukraine, you could continue to see yields move lower from here," said Jonathan Rick, interest rate derivatives strategist at Credit Agricole in New York.
He said that the geopolitical tensions overshadowed concerns of an earlier-than-expected Federal Reserve rate hike. Anticipation of a hike, which would hurt bond prices, has affected U.S. bond markets in recent weeks.
Rick also said if tensions between Russia and Ukraine were to escalate and drive a "complete collapse" in the U.S. stock market, investors may start to believe the Fed will delay its rate hike.
On Wall Street, the benchmark S&P 500 stock index was last down 0.32 percent. (Reporting by Sam Forgione; Editing by Chizu Nomiyama and James Dalgleish)