Most of Sievierodonetsk has fallen to Russia, says governor of Luhansk

Serhiy Gaidai said in an online post late on Tuesday that Russian shelling had made it impossible to deliver humanitarian supplies or evacuate people.

Striuk estimated that about 13,000 people remained in the city out of a prewar population of about 100,000 but said it was impossible to keep track of civilian casualties amid round-the-clock shelling.

The governor of the Luhansk region, Serhiy Gaidai, on Tuesday evening reiterated calls for residents to stay in shelters after he said a Russian airstrike had hit a nitric acid tank, risking the release of toxic fumes. In a post on the Telegram app he added a photograph of a large pink cloud over residential buildings.

Elsewhere on the battlefield, there were few reports of major action on Tuesday.

In the east, Ukraine says Moscow is trying to assault other areas along the main front, including pressing towards the city of Sloviansk.

In the south, Ukraine claimed in recent days to have pushed back Russian forces on a bank of the Inhulets River that forms a border of Russian-held Kherson province.

After having failed to capture Kyiv, been driven out of northern Ukraine and made only limited progress elsewhere in the east, Moscow has concentrated the full force of its armed might in recent days on Sievierodonetsk.

News agencies contributed to this report