Putin orders troops not to storm last Ukrainian military holdout in Mariupol but blockade it 'so not even a fly can get through'

• Putin cancelled plans to storm a Mariupol plant housing Ukrainian forces and civilians on Thursday.
• He instead told troops to blockade the Azovstal steel plant "so that not even a fly comes through."

President Vladimir Putin called off a plan to storm the last Ukrainian military holdout in Mariupol, instead ordering Russian troops to besiege it.

Ukrainian civilians and soldiers are sheltering in the Azovstal steel plant, which has an underground tunnel network.

"This is the case when we have to think, that is, we always have to think, and in this case even more so, about preserving the lives and health of our soldiers and officers," Putin said on Thursday.

"There is no need to climb into these catacombs and crawl underground through these industrial facilities."

Instead, Putin said that Russian forces should blockade the plant "so that not even a fly comes through."

During a televised meeting with Putin on Thursday, defense minister Sergei Shoigu said Russian had "liberated" the city of Mariupol save for the plant.

Putin also said on Thursday that Russia managed to take the city. The claim has not been made by Ukraine or any other countries or international bodies.

The Mariupol city council said Monday that at least 1,000 civilians are sheltering in the plant. It said that the civilians in the plant were mostly "women with children and the elderly."

A Mariupol police official told CNN that supplies of food and water were running low.

Russia recently started dropping bunker-busting bombs on the plant, which are designed to target underground and well-fortified areas, the Associated Press reported.

Mariupol, strategically critical as the largest trading port on the Sea of Azov, has been under Russian bombardment for weeks.

Aid groups have struggled to evacuate civilians and import medical supplies due to Russia's reluctance to observe humanitarian corridors.

The commander of Ukraine's 36th Separate Marine Brigade, who is in the plant, on Tuesday urged other countries to help evacuate people from the plant.