HAVANA, Aug. 19th (Reuters) Two U.S. officials in Germany have been hit by the mysterious “Havana syndrome,” U.S. diplomats told The Wall Street Journal.

These are the first known cases reported in NATO countries, although the officials told the Journal the illness has popped up in other officials in European countries.

The symptoms the officials experienced were severe headaches, ear pain, nausea, fatigue, insomnia and sluggishness, according to the Journal report.

Havana syndrome popped up in 2016 and has affected hundreds of U.S. officials in multiple countries around the world.

Many believe Havana syndrome is caused by radio wave attacks from U.S. enemies.

“There is no evidence about what happened to us, but it is striking that some of us had worked on Russia-related issues,” one worker diagnosed with Havana syndrome told the Journal.

It is not clear what is behind the syndrome, and the State Department has not said whether it is believed to be caused by a U.S. adversary.

Most people who develop Havana syndrome are relocated from their apartments, but symptoms can persist after the move, leading some to believe the culprits are tracking the victims and finding them at the new location, a U.S. official familiar with the situation told the Journal.

While the U.S. conducted an internal investigation of the cases in Germany, it did not notify the German government of the attack. Germany has been a target of disinformation campaigns and cyberattacks from Russia, the Journal noted.

The Russian Embassy in Berlin pointed to earlier denials of the attacks from Russia when asked by the Journal about the U.S. officials who got sick.

Three diplomats told the outlet a self-help group has been set up by Havana syndrome victims and State Department employees as many now fear going abroad due to the attacks and do not believe the government is doing enough to help.

A spokesperson for the State Department told The Hill that anyone who reports symptoms of Havana syndrome receives the care they need, and investigations into how to better protect employees are underway.

These are the first known cases reported in NATO countries, although the officials told the Journal the illness has popped up in other officials in European countries.

The symptoms the officials experienced were severe headaches, ear pain, nausea, fatigue, insomnia and sluggishness, according to the Journal report.

Havana syndrome popped up in 2016 and has affected hundreds of U.S. officials in multiple countries around the world.

Many believe Havana syndrome is caused by radio wave attacks from U.S. enemies.

“There is no evidence about what happened to us, but it is striking that some of us had worked on Russia-related issues,” one worker diagnosed with Havana syndrome told the Journal.

It is not clear what is behind the syndrome, and the State Department has not said whether it is believed to be caused by a U.S. adversary.

Most people who develop Havana syndrome are relocated from their apartments, but symptoms can persist after the move, leading some to believe the culprits are tracking the victims and finding them at the new location, a U.S. official familiar with the situation told the Journal.

While the U.S. conducted an internal investigation of the cases in Germany, it did not notify the German government of the attack. Germany has been a target of disinformation campaigns and cyberattacks from Russia, the Journal noted.

The Russian Embassy in Berlin pointed to earlier denials of the attacks from Russia when asked by the Journal about the U.S. officials who got sick.

Three diplomats told the outlet a self-help group has been set up by Havana syndrome victims and State Department employees as many now fear going abroad due to the attacks and do not believe the government is doing enough to help.

A spokesperson for the State Department told The Hill that anyone who reports symptoms of Havana syndrome receives the care they need, and investigations into how to better protect employees are underway.