Can You Identify These Figurines ???

The head in the background is not part of the set.  LOL

I have friends that purchased these figurines at an estate sale.  The lady they purchased them from told them the figurines came from Vietnam in the 60's.  We are not sure what they are made from.  We do know that they are not made of wood or stone because of the weight and texture.  They may be made of bone, shell, or a plastic type material.  Do these look familiar to you?  Do you know anything about them?  Do you know where this couple could look for more answers??? Thank you for your help.  My God Bless You and Yours!