Water bottles for ablution and head scarves...
I doubt they let Jews have tefellin in jail either. Or Sikhs carry a ceremonial knife at all times. Not everything is a violation of religious rights, some things are dangerous to give people in situations like that. They make a good faith effort, they let them take time for prayer and eat at the right times during Ramadan, they don't make them wear immodest clothing, they can wash up before prayers. I wish they weren't in there, but it's a potentially dangerous place, the ingenuity people have with the materials around them you wouldn't believe.
"Islamically significant" lol who comes up with this stuff.
We are talking about prisons, not schools, although I concede that the distinction is getting fuzzier by the day.