  It is known that monopoles can be confined by vortex-strings in d=3+1 while
vortices can be confined by domain-lines in d=2+1. Here, as a higher
dimensional generalization of these, we show that Yang-Mills instantons can be
confined by monopole-strings in d=4+1. We achieve this by putting the system
into the Higgs phase in which the configuration can be constructed inside a
non-Abelian vortex sheet.
