Ukraine says its forces attacked by Russian troops

A building of a shop, which according to locals was recently destroyed by shelling, is seen in Donetsk, eastern Ukraine January 20, 2015. REUTERS/Alexander Ermochenko

KIEV (Reuters) - Ukrainian President Petro Poroshenko was cutting short a foreign trip on Wednesday after Kiev accused Russian regular forces of attacking its troops in the country's east.

The accusation against Moscow on Tuesday was one of the boldest assertions yet by Ukraine of direct Russian military involvement since the conflict between pro-Russian separatists and government forces began more than nine months ago.