Havana, Jun 11 (IANS): The Cuban government said that it has not uncovered the cause of mysterious health symptoms that affected an official of the US embassy here last month leading to Washington's decision to withdraw personnel posted there.

In a statement on Sunday, the Foreign Ministry said officials launched an investigation after learning an employee had "reported health symptoms as a result of 'undefined sound' in her place of residence", reports CNN.

According to the statement, authorities could not find the source of the sound.

"After more than a year of research by the specialised agencies and experts from Cuba and the US, it is confirmed that there is no credible hypothesis or conclusions adhered to science that justify the actions taken by the government of the US against Cuba to the detriment of the bilateral relationship and with obvious political motivations," it added.

The Cuban response comes after the US withdrew two more people from the American embassy in Havana due to health concerns, according to a senior State Department official.

The individuals in the "potentially new cases" of a mystery illness that has plagued embassy employees have undergone medical evaluations and were not yet "medically confirmed", CNN quoted the official as saying.

US officials have detailed how personnel in Cuba came to experience a variety of symptoms including sharp ear pain, headaches, ringing in one ear, vertigo, disorientation, attention issues and signs consistent with mild traumatic brain injury or concussion.

Last week, a number of US personnel in China have been sent back to Washington for further health screenings after concerns over reports of mysterious acoustic incidents similar to the Cuba "sonic attacks".

Secretary of State Mike Pompeo announced the formation of a task force in response to "unexplained health incidents" affecting US diplomats and their family members.