People in the former Soviet Union have a long way to go in regards to their attitude towards the GLBT community. Most of their intolerance doesn't even stem from religious morals. When the former republics were living under Soviet times, being gay was considered "counterproductive" in the socialist path towards communism. Hence, homosexuality was greatly discouraged and criminalized.
Since then, it's been a big mess of things with most former Soviet republics struggling to stabilize their economy since adopting capitalism. Some countries have maintained rather strong Soviet influences (such as Belarus, Turkmenistan, Tajikistan, and parts of Moldova) while others have moved far away as possible from their Soviet past (Lithuania, Estonia, Latvia, and Georgia). The Baltic republics of Latvia, Lithuania, and Estonia have always been the most economically prosperous republics of the USSR and have maintained the highest standards of living compared to the rest of the former republics. They have also joined the European Union. However, they still hold fairly conservative views towards gays in comparison to the rest of Western Europe.
This really is nothing unusual over there. Fortunately those people will eventually let go after a good bribe to the police. But in general, Belarus faces a lot of problems with its people regarding opposition of their president, Alyanskandr Lukashenka. I'm honestly even surprised this video managed to make it online in the first place (and in Belarusian for that matter!).
It will be interesting to see how Moscow Pride will work out because that has been a failed attempt already the past few years.