Not yet.

This is something we are considering to add in future versions.

Meanwhile, we invite you to enter our Feature Request page and post your suggestion there, or join an existing similar suggestion. Unfortunately it is not possible for us to integrate every suggested feature into Viber, but the more people join on a request, the faster it will become reality
You can find it here: http://viber.kayako.com/Knowledgebase/Arti...r-a-new-feature