US troops syria
© US Army/Spc. Jensen Guillory
The US is investigating what appears to be directed-energy attacks on US troops, and the Pentagon suspects Russia is behind them, Politico reported.

Four national-security officials involved in the investigation told Politico that the Department of Defense has been investigating the incidents of suspected attacks since last year.

Two sources told Politico that this included incidents in Syria, where troops developed flu-like symptoms last fall.

Politico also reported that the Defense Department has briefed lawmakers on intelligence about the suspected attacks.

But a Pentagon spokesperson told Politico that the Defense Department wasn't aware of directed-energy attacks against troops in Syria.

Insider has contacted the Department of Defense for comment.

Directed-energy attacks involve directing energy towards a particular target, and could involve methods like lasers. It can involve directing microwave energy towards people, which harms people's health.

US officials in Cuba, China, and Russia have previously become mysteriously sick, and studies have pointed to microwave radiation as the main suspect.