WASHINGTON (Reuters) - The U.S. Treasury department on Friday sanctioned Singaporean Yin Kechen and cybersecurity company Sichuan Juxinhe Network Technology Co., accusing both of being involved in a series of hacks against American telecom companies.

The intrusions, known under the name "Salt Typhoon," have allegedly exposed a huge swathe of Americans' call logs to Chinese spies and rattled the U.S. intelligence community. In some cases, the hackers are alleged to have intercepted conversations, including between prominent U.S. politicians and government officials. Some lawmakers have described them as the worst telecom hack in America's history.

In a statement, the Treasury described Sichuan Juxinhe Network Technology Co. as a hacking company with "strong ties" to China's Ministry of State Security (MSS), an intelligence agency. It said that Yin Kechen had worked as a hacker for over a decade and also had ties to the MSS. It further alleged that he was tied to the recent breach at the U.S. Treasury.