Researchers at Qurium Media Foundation analyzed the blocking implemented by four different operators in Belarus. Block techniques include transparent web proxies, injection of HTTP responses, stateless and stateful SSL DPI and fake DNS responses. Some of the blocking techniques used include Domain Name System spoofing, transparent proxies with hijacked HTTPS certificates and Deep Packet Technology (DPI) implementations. According to Quriums report, providers use their own infrastructure to implement the blocking and blocking is therefor not implemented on a central level.”]
Source: https://securityaffairs.co/wordpress/108655/hacking/belarus-internet-blocking.html