All mines are "phased out" regardless of faction.
There are only 2 ways to clear a minefield:
1. Use a scout (Arcova Scout Frigate, Seeker Vessel, Jikara Navigator). It can reveal mines within a certain radius (displayed if you select the scout and however over the passive). Once being revealed the mines can be targeted and destroyed.
2. Give one or more DURABLE ships a move order to every single mine..... they will detonate then. This is often quicker than moving in a scout, however it requires some ships that can take the punishment.