yes it's not an offence to be arresting them since they're not causing any nuisance to the public but may be told to leave
actually the polis won't really disturb them other than to check their identity if they look suspicious or loitering around
as for *shelter homes, there are a few around
a matter of them being comfortable to share the space w/ other homeless peeps or felt that the location is too far away to their liking
* shelters that aren't a permanent home stay.
where they can check in at night & having to leave the premises by 7am.