Children's ombudsman Pavel Astakhov says thousands of refugees from Ukraine have been fleeing to Russia every day.
"Over the past day, 8,386 Ukrainian citizens entered the Rostov region from Ukraine. At the refugee camp, where we were yesterday for an inspection, 151 children arrived," Astakhov said Thursday on his Instagram account.
Ukraine's border service disputed the report, however, saying that there was no record of even a single Ukrainian citizen seeking refugee status at the border, RIA Novosti reported Thursday.
Astakhov made a similar claim about refugees on Tuesday, when he said more than 7,000 Ukrainian refugees had entered the country within a day.
Russian officials have pointed to alleged streams of refugees throughout the Ukraine crisis as a sign that the new Kiev government is unable to keep the situation under control.
The Ukrainian authorities began a counterterrorist operation in mid-April in the southeastern region of the country to tackle pro-Russian, separatist groups. Slovyansk and Luhansk have both seen heavy fighting in recent days as government forces clashed with pro-Russian rebels.