Quote:Users of Telegram Messengers in certain parts of the world had trouble exchanging messages through the service today. The problems were caused by a distributed denial-of-service attack aiming at Telegram servers.

The service outage affected users mainly in South and North America, although connection issues were present in other parts of the world as well.
 
In a Twitter announcement, Telegram informed that its servers today were the target of a DDoS attack deployed by a network of compromised computers.
 

Quote:We’re currently experiencing a powerful DDoS attack, Telegram users in the Americas and some users from other countries may experience connection issues.
— Telegram Messenger (@telegram) June 12, 2019

Quote:Update [06.13.2019]: Pavel Durov said on Twitter that the attacking IP addresses were coming mostly from China.
"Historically, all state actor-sized DDoS (200-400 Gb/s of junk) we experienced coincided in time with protests in Hong Kong (coordinated on @telegram). This case was not an exception," said Telegram's founder.