On June 10 the Cuba Foreign Ministry stated, “ After more than a year of investigations by specialized agencies and experts from Cuba and the United States, it is confirmed that there is no credible hypothesis or conclusions attached to science that justify the actions taken by the United States government against Cuba in detriment of bilateral relations and with obvious political motivations.”
This statement came after the U.S. on June 8 publicly announced that two more officials of the U.S. Embassy in Havana had reported health symptoms as a result of “undefined sounds” in their residence, but that these two individuals were considered “potentially new cases,” but had not yet been “medically confirmed” before testing at the University of Pennsylvania. 
According to the subsequent Cuba statement, it learned of one of the new cases on May 29 and immediately did an “exhaustive and urgent investigation carried out in the vicinity of the residence [and] found no evidence of any sound that could cause damage to health.”
In addition, the Ministry reiterated “that no evidence has been presented of the alleged incidents and maintains its unwavering commitment to cooperate with the authorities of the United States to achieve clarification of this situation and the best medical attention to the persons concerned.“ (Emphasis added.)
Nevertheless, Cuba “publicly and officially reiterated its willingness to cooperate seriously in the joint search for answers, clarification and the solution of the alleged facts.”
All of this happened after the U.S. had disclosed that some diplomatic employees at a U.S. consulate in southern China had reported medical symptoms similar to those that had occurred in Cuba.
 MINREX statement, There is no credible hypothesis about alleged sonic attacks, Cubadebate (June 10, 2018); Reuters, Cuba Says Cause of Illness in U.S. Diplomats Remains Mystery, N.Y. Times (June 10, 2018); Assoc. Press, Cuba Releases Details of Incident Involving US Official, N.Y. Times (June 10, 2018).
 Assoc. Press, US Pulls 2 More From Cuba Amid New Potential Health Cases, N.Y. Times (June 8, 2018); Reuters, Two People From U.S. Embassy in Havana Evaluated for Illness–State Department, N.Y. Times (June 8. 2018).
 U.S. State Dep’t, Message for U.S. Citizens [in China]: Improvements to Safety and Security Information (June 8, 2018); Perlez & Myers, U.S. Issues Alert to Americans in China in Wake of Sonic Attack Fears, N.Y. Times (June 8, 2018); Perlez & Myers, China Pledges to Investigate Fears of Sonic Attacks on U.S. Diplomats, N.Y. Times (June 7, 2018); Myers & Perlez, A Medical Mystery Grows as U.S. Consulate Workers in China Fall Ill, N.Y. Times (June 6, 2018).