According to a local Ukrainian governor, a Russian aircraft hit a nitric acid tank in the frontline city of Severodonetsk.

Serhiy Gaidai, encouraged area residents not to leave bomb shelters because of the poisonous gases from the acid tank.

Mr. Gaidai also included a photo of a big pink cloud hovering over apartment towers.

He didn’t say if there were any casualties.

“Residents of the region do not come out of hiding,” he wrote.

Russian forces make Severodonetsk a main objective in their advance.

They see it a focal point in the fight.

If Russia takes the city, it would gain control of the entire Luhansk area, and it will be Russia’s biggest win in the assault thus far.