This is incredibly sad. I spent a few weeks in Belarus last summer (2019) and everyone seemed incredibly hopeful and positive. It's a beautiful country and Minsk is a gorgeous city.
I've been able to contact a few of my friends there sporadically over the past few days, but have heard nothing from them for 24 hours. Initially it seemed like a block on communication apps like WhatsApp and they could get around it with a VPN but now it seems that it's turned into a full internet shutdown.