Three of them -- Wang Xin, Song Chen, Zhao Kaikai -- are under arrest while the Federal Bureau of Investigation (FBI) is seeking to arrest the fourth, Tang Juan, who is said to be at the Chinese consulate in San Francisco, the BBC report said citing a Department of Justice statement as saying on Thursday.
Wang was arrested on June 7, while Song and Zhao were both arrested on July 18.
Wang has disclosed that he remains a People's Liberation Army (PLA) member, and works at a military university lab, the statement said, having stated on his visa that he had left the military in 2016.
Prosecutors have alleged that Song claimed to be a neurologist who had left the armed forces but was still affiliated with PLA Air Force (PLAAF) hospitals in China, while Zhao claimed never to have served in the military but in fact was a member of a top PLA research institution, according to the Department.
Tang is thought to be a member of the PLAAF. An agent found photos of her in military uniform and evidence that she worked at an air force medical university
In the statement, Department attorney John C. Demers said that members of PLA applied for research visas while hiding their "true affiliation" with the military.
"This is another part of the Chinese Communist Party's (CCP) plan to take advantage of our open society and exploit academic institutions," the BBC report quoted Demers as saying in the statement.
FBI agents have interviewed people in 25 US cities who have an "undeclared affiliation" with China's military, the Department of Justice added.
Thursday's development came two days after American officials ordered the closure of China's mission in Houston, saying it was involved in stealing intellectual property.
Hours after the charges were announced US Secretary of State Mike Pompeo denounced a "new tyranny" from China, the BBC reported.
Speaking at the Richard Nixon Presidential Library in California, Pompeo on Thursday called on "on every leader of every nation" to stand up to China, adding that securing freedoms from the CCP was "the mission of our time".