Newly spawned in zombie pigmen keep attacking me even after the 20-40 rage timer and if they are out side of a 32 block range

So a friend hit a zombie pigman that was no where near any other pigmen then as we were about to explore for a fortress. All the Pigmen started attacking us we left the nether to try and despawn the pigmen but that didn't work. we tried on going but newly spawned in pigmen that were further ten 32 blocks started to kill us and there rage is still going on its been about 20 mins so far as I'm typing this and newly spawned pigmen just keep coming. plz help