Two Russian naval vessels have been fitted with a defensive weapon, which, during testing, caused some subjects to hallucinate and vomit because of its disorientating effect.

RIA Novosti, Russia’s domestic state news agency, reported that a Russian military contractor had begun supplying the navy with the weapon, a “visual optical interference” device, named Filin 5P-42. The weapon’s name "Filin" translates to "Eagle Owl" in English.

The technology, which was developed to dazzle and incapacitate attackers, has been deployed on the Russian naval frigates Admiral Gorshkov and Admiral Kasatonov, according to a news release from Ruselectornics, which created the Filin system.

9News reported that the weapon fires a beam, similar to a strobe light, which hinders the enemy's ability to see the ships. Weapon can also suppress night vision technology, laser targeting systems and anti-tank missiles up to a distance of more than three miles.

Testing of the weapon found that volunteers who attempted to hit targets protected by the Filin with sniper rifles, assault weapons and machine guns all experienced difficulty with aiming. They were unable to see the target.

Almost half of the test subjects, 45 percent, said they experienced dizziness, nausea and feelings of disorientation, according to RIA Novosti. A further 20 percent said they suffered hallucinations and described a “ball of light moving in front of the eyes.” The manufacturer has also claimed the device can temporarily blind attackers.

Two further warships, currently under construction, are expected to be fitted with the device as well as the Gorshkov and the Kasatonov, which are currently patrolling the Arctic Ocean.

Russian and U.S. relations reached a new nadir Saturday after Moscow withdrew from a landmark Cold War nuclear treaty. The Russian pullout was precipitated by the U.S.’s withdrawal one day earlier from the Intermediate-Range Nuclear Forces Treaty (INF), signed by the U.S. and USSR in 1987.

President Donald Trump and U.S. defense officials have accused Russia of developing weapons that contravene the treaty. Announcing the U.S. withdrawal, Secretary of State Mike Pompeo said: "For years, Russia has violated terms of the INF Treaty without remorse."

The U.S. withdrawal came into effect on February 2. Russian President Vladimir Putin said on the same day that the Kremlin would push ahead for its designs to develop new nuclear-capable missiles, including supersonic ones.

This article has been amended to state that some aspects of the Filin weapon's capabilities were first reported by 9News.