Officials have warned that Mariupol could be in danger of cholera after it was repeatedly bombed and besieged for several months by Russian forces.

A consultant to the mayor of the occupied port city said Tuesday that the water supply had been contaminated with decomposing bodies and garbage, increasing the possibility of cholera.

Petro Andryushchenko, a Ukrainian television host, stated that the word “cholera” is not just coming from us but also inside the city.

He said that officials from the city had been informed by Russian city officials that they were preparing infected disease units for a possible cholera outbreak. This could have an impact on Russian troops at Mariupol. He stated that the World Health Organization and the United States recognize the threat, as do the occupants.

Andryushchenko claimed that Russian authorities were closing down Mariupol and creating a quarantine.

He said that the situation was “really quite dangerous” and added that he hoped the Russians would permit epidemiologists, either Ukrainian or international, to enter the city to help manage the situation.

NBC News was unable to confirm the claims of Andryushchenko.

After Mariupol’s council had warned last week that the Azov Sea port was at risk of an epidemic, they arrived. According to the council, the city is “literally drowning” in garbage and sewage because its central water supply and sewer systems are down. It said that the summer heat has accelerated the decomposition under the rubble of thousands of bodies.

The council quoted Vadym Boychenko, Mariupol Mayor, as saying Friday that dysentery and cholera could kill tens to thousands of people living in the ravaged city.

According to WHO, Cholera can be fatal if it is not treated. To prevent and control the spread of Cholera, it is essential to provide safe water and sanitation.

Last month, the WHO warned Mariupol about the possibility of an outbreak of infectious diseases. Citing information from nongovernmental organizations, the WHO stated that Mariupol’s drinking and sewage water were becoming mixed. This created “a significant hazard for many types of infections including cholera.”

Margaret Harris, spokesperson for WHO, stated Tuesday that Mariupol is at high risk of cholera. She cited a public health analysis she had published earlier in the year.

“However, in the absence of systematic epidemiological investigations and laboratory testing (PCR), we are unable to confirm whether there is an outbreak.”

Harris said that Mariupol access is still difficult and that the WHO was seeking opportunities to do this through its partners on ground.

Residents of Mariupol were subject to months of heavy bombardment during the Russian siege. They had no food, water or medicine and were left without electricity or food for several months. This raised fears of a humanitarian disaster. Russia took control of Mariupol last month, after the last Ukrainian defense force surrendered at the Azovstal Steel plant.

According to Ukrainian officials, more than 20,000 people have been killed in the city.

Many were forced to be buried in their backyards or in large graves because of heavy shelling. Officials in Ukraine fear that others might have been trapped under the rubble of demolished buildings and their bodies may not be retrieved.