Kiev (AFP) - Ukraine's interior minister said on Saturday most pro-Russian rebels and their top commander had fled their eastern stronghold of Slavyansk in Kiev's biggest success of the nearly three-month campaign.

"This morning, intelligence reported that Girkin (Igor Strelkov) and a substantial part of the rebels had fled Slavyansk," Ukraine's Interior Minister Arsen Avakov said in reference to the industrial city of nearly 120,000 which the insurgents seized on April 6.