American and British officials on Monday leveled accusations, imposed sanctions, and attacked Beijing over a wide-ranging cyber espionage campaign said to have affected millions of people - including legislators, academics, journalists, and others.

Authorities on both sides of the Atlantic accused the hacking group known as "APT31" of being an arm of China’s Ministry of State Security, targeting a long list including White House staff, US senators, British parliamentarians, and government officials worldwide who criticized Beijing. Officials said defense contractors, dissidents, and security firms were also targeted.

In an indictment unsealed on Monday against seven alleged Chinese hackers involved, American prosecutors said the hacking led to confirmed or potential breaches of work accounts, personal emails, online storage, and phone call records belonging to millions of Americans.

Deputy Attorney General Lisa Monaco said in a statement that the goal of the global hacking operation is “to suppress critics of the Chinese regime, harm government institutions, and steal trade secrets.”

The Chinese embassy in Washington did not immediately respond to a message seeking comment on the US charges, but the Chinese embassy in London described previous UK accusations as “entirely fabricated and malicious slanders.”

Reuters was not immediately able to identify contact information for the seven alleged hackers charged by the Department of Justice.

The announcements came as both Britain and the United States imposed sanctions on a company they said was a front for the Ministry of State Security.

The US Treasury Department said in a statement that sanctions were imposed on Wuhan Xiaorui Zhi Technology Co., Ltd., as well as on Chinese nationals.