North Korea is reported to have created a “nuclear backpack” special military unit tasked with spraying toxic radioactive materials at the enemy.

The U.S.-based Radio Free Asia(RFA) on Wednesday quoted a source in the North Korean province of North Hamgyong as saying that Pyongyang created the nuclear backpack troops in March.

The unit is said to consist of soldiers selected from the scout platoons and light infantry brigades under the Korean People’s Army.

Another North Korean source residing in Yanggang Province told RFA that the regime is telling the soldiers that nuclear backpacks are not designed to detonate nuclear bombs, but spread radioactive substances over a wide area.

Last October, the North displayed soldiers carrying backpacks emblazoned with nuclear radiation symbols during a military parade marking the 70th anniversary of the North’s Workers’ Party.

It also showed a truckload of soldiers wearing the backpacks during a military parade in 2013.