Ukraine's General Staff said Russian forces are continuing to "launch artillery and air strikes on Mariupol" while blocking Ukrainian units near the Azovstal plant.

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"In order to establish full control over the city and suppress the resistance of Ukrainian defenders, it uses strategic aviation. Given the evacuation of the local residents, increase of the firing should be expected in the near future," the General Staff said.

Zaporizhzhia and Enerhodar

The regional administration in Zaporizhzhia said there are signs the Russians are trying to reinforce their units by bringing in more equipment and troops. It said a new Russian contingent had arrived in Mykhailivka, just south of current frontlines.

In the nearby city of Enerhodar, occupied by Russian forces since early March, the regional administration reported on Friday that, "The city is almost out of medicine, and humanitarian aid is not always available." Enerhodar residents, it said, are "already afraid to go to protests and organize rallies" because of constant patrols and intimidation by Russian soldiers.