Viktor Yanukovych

Russia scrambled fighter jets to patrol its border and reportedly gave shelter to Ukraine's fugitive president as pro-Russian gunmen stormed offices of Ukraine's strategic region of Crimea, deepening the crisis for the new Ukrainian government even as it was being formed.

Ukraine's acting government issued a warrant Monday for the arrest of President Viktor Yanukovych, last reportedly seen in the pro-Russian Black Sea peninsula of Crimea, accusing him of mass crimes against protesters who stood up for months against his rule.

The whereabouts and legitimacy of Ukrainian President Viktor Yanukovych were unclear on Sunday, after he left the capital and his archfoe Yulia Tymoshenko was freed from prison and returned to Kiev to address a massive, adoring crowd.

Ukraine's presidency said Friday that it has negotiated an international deal intended to end battles between police and protesters that have killed scores and injured hundreds. It was unclear whether the deal would appease protesters, and shots rang out Friday morning in central Kiev.