During WWII, the Japanese developed the AA Mine Discharger anti-aircraft weapon. It was a standard infantry mortar but instead of bombs, it was loaded with 7 mines with parachutes.

When fired the shell was thrown 3000 to 4000 feet in the air. The shell would eject the mines at the top of the arc. Then the mines would float down with their parachutes. The mines would detonate on contact or after a fixed period of time.

The issue with it was that planes could avoid the mines. Also, the winds would change sometimes sending the mines back to the location of where they originated.