MOSCOW (Sputnik) — The National Guard said the cyberattack took place at 14:00 GMT on Wednesday.
"Rosgvardia's main communication department experts have established that the site has undergone a massive DDoS attack from multiple network requests," it said.
The National Guard said it is conducting countermeasures to thwart the attacks and restore the website's operability.
A DDoS-attack is an attempt to make an online service unavailable by overwhelming it with traffic from multiple sources.