Sievierodonetsk, the main focus of the fighting in eastern Ukraine in recent weeks, isn't yet blocked off by Russian troops even though they control about 80% of the city and have destroyed all three bridges leading out of it, an official said Tuesday.

"There is still an opportunity for the evacuation of the wounded, communication with the Ukrainian military and local residents," Luhansk regional governor Serhiy Haidai told The Associated Press by phone.

Still, Haidai acknowledged that the mass evacuation of civilians now is "simply not possible" due to the relentless shelling and fighting in the city. Ukrainian forces have been pushed out to the industrial outskirts of the city because of "the scorched earth method and heavy artillery the Russians are using," he said.

About 12,000 people remain in Sievierodonetsk, a city with a pre-war population of 100,000. More than 500 civilians are sheltering in the Azot chemical plant, which is also being relentlessly pounded by the Russians, according to Haidai.

In all, a total of 70 civilians have been evacuated from the Luhansk region over the past 24 fours, the governor said.

Two people were killed and another wounded in the Luhansk region, according to Ukrainian authorities.