North Korea has been warned. Now, they've done this.

Update: The U.S. Pacific Command has confirmed that North Korea fired three short-range ballistic missiles. The first and third failed in flight, while the second appears to have detonated upon launch, CNN reports.

North Korea has fired several short-range projectiles into the sea off the east coast of the Korean Peninsula, according to reports out of South Korea.

The Daily Express reports that Japanese officials believe these to be ballistic missiles.

The South Korean military is analyzing the projectile to determine whether or not the projectiles were ballistic missiles. This launch could indicate North Korea is continuing to conduct missile tests in the face of U.S. pressure to refrain from threatening acts or rhetoric towards the U.S. and its allies.

The United States and South Korea are in the midst of an annual 10-day series of military exercises that are used to establish defense techniques. North Korea has long pushed back against these exercises, viewing them as confrontational.

North Korea responded to the joint exercises by vowing "merciless retaliation."

The U.S. Treasury Department just sanctioned 10 firms and six individuals this week for involvement with North Korea. The targets of the sanctions included Chinese and Russian firms and individuals.