"Traders would be foolish to make the mistake they made two weeks ago and go home long into the weekend, particularly with the situation on the ground in Ukraine so potentially fluid, and the Crimea referendum vote due on Sunday," says market analyst Michael Hewson.
However, U.S. stock futures are higher following sharp losses on Wall Street yesterday.
Euro Stoxx 50 -0.6%, London -0.4%, Paris -0.6%, Frankfurt -0.7%, Milan -0.5%, Madrid -0.7%.
U.S. stock futures: Dow +0.1%. S&P +0.2%. Nasdaq +0.2%