Listing all Child pages

Hi,

I’ve read everything the codex has to say regarding child pages but my problem has yet to be solved.

Example:

Asia (Parent page)
-> Japan (Child page)
-> India (Child page)
-> Singapore (Child page)
-> Vietnam (Child page)

On the child page “Singapore”, I wanna list out all child pages within the “Asia” parent page (eg: Japan, India, Singapore and Vietnam).

How do I do this?