I would like to know a proof of a variant of Hardy's inequality below. Could anyone introduce me a reference or give me a proof? Thank you very much for your assistance.

Set $0<r<\frac{2(n-s)}{n-2}$, $0<s<2$ and $n\ge 3$. Let $\Omega \subset \mathbb{R}^n$ be a bounded domain with smooth boundary. Them there exists a constant $C>0$ such that $$ \int_{\Omega}\frac{|u|^r}{|x|^s}dx\le C\int_{\Omega}|\nabla u|^2dx $$ for any $u \in H^1_0(\Omega)$.