C-RAM, which has been installed in the Green Zone, can blast mortar projectiles right out of the sky. Less of an issue than you’d think.
Here’s C-RAM blowing mortar shots away in Iraq: https://www.military.com/video/defense-systems/air-defense/c-ram-shooting-incoming-mortars/2036347233001
Yeah that’s cool - saw a better one shooting down incoming rockets - but like most defenses, they have limited ammo, and the enemy knowing that can overwhelm the best defense. A heavy mortar attack would guarantee a few rounds would land on your miniguns.
We could probably return fire to the locations that the mortar fire came from faster then they could leave those locations, but I'm not sure about that though, but it won't surprise me if they could.