Deleting Mercurial repositories using API

[mistermiros]

Most of our repositories were using Mercurial, but because of ending support we migrated them to Git, but haven't deleted old Mercurial ones and just added ".hg" suffix to them. Now, we are trying to mass delete them using API (there a are about 300 hundred of them), but we're getting this error "You can't delete the repository while it is in read-only mode." Can read-only Mercurial repo be deleted using API or we must delete them manually?