North Korea’s military has 300 to 400 attack drones capable of carrying biological and chemical weapons that could reach the South Korean capital of Seoul within one hour, according to a high-level defector from the isolated regime ruling Pyongyang.

The claim from a 42-year-old former third secretary who fled Kim Jong-un’s regime in 2015 coincides with heightened international concern over a different threat from North Korea: mobile, medium- to long-range missiles that Pyongyang has tested with increasing frequency.

After successfully launching one of the solid-fuel missiles Sunday, North Korean leaders said they are ready to begin deploying and mass-producing the Pukgukson-2 projectiles, which Pyongyang says are capable of reaching major U.S. military bases in Japan.

The Sunday launch was the latest of more than 70 North Korean missile tests since 2009, resulting in a U.S. and regional focus on countering the ballistic missiles.