If I already live in China, can I adopt a child through American agency or Chinese attorney?

This is HK again. I realized that the heading I used wasn't clear. I meant to write:
Could an American citizen living in China adopt through a Chinese agency or attorney?

My sister recently adopted a boy from China, so I know something about the process for a person living in the U.S.

I have applied for a job in China, and am interested in adopting a child there. I saw the information that a person already living in China must go through the same process, so I assume that includes a home study, and the use of an adoption agency. If so, would the agencies have to be American agencies, or are there Chinese agencies or attorneys that handle cases for people already living in China?