The jail administration said that during an antigen test of 817 inmates, 228 tested positive for the virus including one staff member.
There are 1,049 inmates in Ballia prison. With Ballia's tally, the total number of prisoners infected in the state has reached 486. Besides, 25 jail staff, too, have tested positive.
All the prisoners were tested through rapid antigen kits and samples of those tested positive have also been sent for confirmatory RT-PCR test.
UP Chief Minister Yogi Adityanath had earlier instructed all the districts to set up temporary jails. A communique was also issued by the home department in connection with the same.
However, Ballia district magistrate Shrihari Pratap Shahi, admitted that there was no facility of temporary jail in the district. "We had set up such jails only for 'Tablighi Jamaatis'," he added.
Shahi further said that large-scale sampling was done in the jail after which 16 inmates tested positive for the virus on July 22.
"Following that, we organised a larger camp of 20 medical teams and got a maximum number of inmates tested," he said.
He also said that several measures have been taken to limit the spread of the virus.
"Of the total eight barracks, three barracks have been turned into isolation wards, for those coming from outside. A team of the health department has been asked to deploy its unit inside the prison," he said.