I play both basketball and volleyball. In my experience, they could both me considered "dangerous". My team mate shattered her knee in basketball, and I've nearly broken my wrist in volleyball. But.. it's all part of the game.
Coming from a coach's perspective i would say both sports have their pro's and con's. In my opinion both sports are equal when it comes to injuries. Because the same injuries u may get playing basketball are the exact same possibility in volleyball.