MOSCOW (Reuters) - Leaders of pro-Russian separatists in Ukraine have refused to sign an agreement in Minsk, TASS news agency quoted a source as saying on Thursday.

The arrival at talks in the Belarussian capital Minsk of two leaders of the rebel-held Donetsk and Luhansk regions in eastern Ukraine had raised hopes of an agreement, aimed at ending fighting in a conflict that has killed more than 5,000 people.