Worship or other religious acts performed by a detainee alone must not be prohibited or restricted; provided, however, that this does not apply if there is a risk of hindrance to the maintenance of discipline and order in the immigration detention center, etc. or otherwise to its administration and operation.
Read this with the articles around it
immigration detention center, etc.machine translation
「入国者収容所等」
An immigration detention center, or a detention facility set up at a regional immigration services bureau under Article 55-3(1).
Defined inArticle 2, paragraph (1), item (xvi)· applies throughout the law
detaineemachine translation
「被収容者」
A person held in an immigration detention center or other immigration detention facility.
Defined inArticle 55-4, paragraph (1)· applies only in this chapter and in Article 71-6