A Russian border security official said more than 400 Ukrainian soldiers crossed into Russia, according to a report from the Interfax news agency. It wasn't immediately clear why the soldiers entered Russia, with both sides giving conflicting accounts. The Russian official said the soldiers deserted the Kiev government and the Russian side opened a safe corridor, while a Ukrainian military official said the soldiers, without giving a number, were forced into Russian territory by rebel fire after running out of ammunition, AP reported. Vasily Malayev, head of the Federal Security Service's border patrol in the Rostov region, told Interfax that 438 Ukrainian soldiers had reached Russia on Monday. He said the Russian side had allowed the soldiers to safely enter the country.