More now from Luhansk regional administrator, Serhiy Haidai, who has urged locals to evacuate immediately from the region as Russian forces continue their assault.
Earlier, he said 50 people had been evacuated from the eastern cities of Lysychansk and Severodonetsk in the Luhansk region and taken to safety.
"Today we will take everyone out," he posted on Telegram.
Ukrainian troops have left the city of Kreminna in eastern Ukraine and taken up new positions, Reuters quoted Haidai as saying.
"Kreminna is under the control of the 'Orcs' [Russians]. They have entered the city," Haidai told a briefing.
"Our defenders had to withdraw. They have entrenched themselves in new positions and continue to fight the Russian army."
He said Russian forces had attacked "from all sides".