It's worth remembering that the Iranians have as yet never claimed that the strait is mined. They have said that it may be. A lot of reporting misses this and assumes (perhaps deliberately) that the presence of mines is a fact.

But of course Iran doesn't need mines to enforce the blockade. They have drones and missiles that can be operated safely from 100's of kilometres away. They have anti-ship sea-skimming missiles. Not to mention the very large fleet of small armed fastboats.