Wall St. falls, but up for third straight week

NEW YORK (Reuters) - Stocks ended mostly lower on Friday as Ukraine-Russia tensions reignited and remarks from Federal Reserve Chair Janet Yellen failed to give investors more clues on interest rate hikes.

The Dow Jones industrial average fell 38.46 points or 0.23 percent, to 17,001.03, the S&P 500 lost 4.01 points or 0.2 percent, to 1,988.36 and the Nasdaq Composite added 6.45 points or 0.14 percent, to 4,538.55.

For the week, the Dow is up 2 percent, the S&P is up 1.7 percent and the Nasdaq is up 1.6 percent. It is the strongest week of gains for both the Dow and S&P since April, and the third straight week of gains for all three indexes.

(Reporting by Ryan Vlastelica; Editing by James Dalgleish)