Caching RJS fragments

Do you have any hint for using fragment caching within a RJS response? I've the following piece of code in a rjs template

for hotel in @hotels   cache(:id => hotel.id, :format => params[:format]) do     page.insert_html(:bottom, :items, :partial => hotel, :locals => { :city => @city, :country => @country })   end end

but when the response is rendered it returns the following error, probably because cache expects an ERB template.

ActionView::TemplateError (undefined local variable or method `_erbout' for #<ActionView::Base:0x20b8e00>) on line #2 of hotels/ index.js.rjs:

I searched the newsgroup and I read thousand of blog posts but I haven't been able to figure out a reasonable solution. Any suggestion?