An adviser to Mariupol's mayor said Russian forces have announced the besieged city would be closed for entry and exit on Monday, warning men remaining in the city would be "filtered out."
Petro Andriushchenko, the mayor's adviser, said on Telegram on Sunday Russian forces had begun issuing passes for movement within the besieged city, posting a photo purportedly showing residents lining up for the passes.
"Hundreds of citizens have to stand in a line to get a pass, without which it will be impossible not only to move between the districts of the city, but also to go out on the streets starting next week," he said.
In a separate statement Saturday, Andriushchenko said Russian forces announced the city would be "closed for entry/exit for everyone from Monday, but there will also be a ban on moving around the districts for a week." Andriushchenko added, according to information received from inside the city, men in the city will be subject to "filtration" -- relocated for screening by Russian forces.
CNN cannot independently verify the claims by Andriushchenko, who is not in Mariupol but works to gather information collected from people in the city, which has been under a weeks long siege.
Ukrainian and US officials have alleged Russian forces have carried out filtration of civilians in areas under their control, biometrically screening them, confiscating their phones and, in some cases, deporting them against their will into Russia. The Mariupol City Council has alleged filtration was part of a broader effort by Russia to cover up potential war crimes carried out in the city.
Ukrainian forces defending the city earlier rebuffed an ultimatum from the Russian Ministry of Defense calling on Ukrainian soldiers in the city to surrender.