"Searches are being made to locate the two prisoners," Joint Commissioner of Police (Crime) Pallab Kanti Ghosh told PTI.
The two prisoners, Mohammad Sabuj and Mohammad Ali Ahmed, were arrested in May under the Foreigners Act, Ghosh said.
Ghosh said he visited the jail and talked to the authorities.
Forensic experts visited the jail and collected fingerprints.
Jail sources said the two, engaged in sweeping, were suspected to have scaled the wall from the backyard of the jail kitchen.
They were found missing during the evening roll call yesterday.
Meanwhile, security in the jail, where several Maoists are lodged, has been tightened.