Reports that Ukrainian forces attacked Russian military vehicles that had crossed the border rattled US stock markets, knocking them down in the afternoon and sending traders into the safety of US government bonds.

GLOBAL stocks staged the biggest rally of 2011 yesterday and the Dow Jones Industrial Average reached an almost three-year high amid better- than-estimated results at companies from Intel to United Technologies and L’Oreal.

US stocks closed slightly lower today as investors’ pessimistic view of the economy deepened.