KIEV, Aug. 28 - Ukrainian debt spreads widened and stocks fell on Thursday amid growing investor concerns that tensions with Russia may escalate and hurt the economy.

Ukraine's portion of the sovereign debt benchmark was 4 basis points wider, in contrast to the overall index which narrowed 5 basis points at 305 basis points over U.S. Treasuries, Reuters reported.

The PFTS stock index fell 29.79 points to 513.84 in Kiev trading on Thursday, pushing the index down 56.2% since the beginning of the year, making it one of the worst performing markets in the world.