Judiciary spokesman Gholamhossein Esmaili told reporters the inmates were allowed out of prison after testing negative for Covid-19 and posting bail.
"Security prisoners" sentenced to more than five years will not be let out.
The jailed British-Iranian charity worker Nazanin Zaghari-Ratcliffe may be freed soon, according to a British MP.
Tulip Siddiq cited the Iranian ambassador to the UK as saying that Ms Zaghari-Ratcliffe "may be released on furlough today or tomorrow".
Her husband said on Saturday that he believed she had contracted Covid-19 at Tehran's Evin prison and that authorities were refusing to test her.
But Mr Esmaili insisted on Monday that Ms Zaghari-Ratcliffe had subsequently been in contact with her family and "told them about her good health".