What sets off proximity bombs?

[harken23]

Usually Deke doesn't set them off, but sometimes he does. And just now, it went off when I set it, and there wasn't an enemy anywhere nearby. Plus, it's instant death when that happens. Annoying.

[simon.pete15]

Any one person getting close enough sets them off.
If a dead body is close enough, it'll go off as Deke sets it.
However, if you get close and hit the action button, Deke can pick it up without it going off. Once the red light shows, or you hear the warning beep, or see the red explosive diamond, get away ASAP. A couple of rolls away is a good start, if you're low when it goes off you might survive it :)

[harken23]

Deke doesn't set it off, I just wondered why it went off when I set it.

[simon.pete15]

Deke will set off his own proximity bombs. If he's close enough to pick one up, and doesn't, it'll go off.

[harken23]

I've run straight over them a bunch of times, and they don't go off... Or maybe I didn't step directly on them?

[Immortal Cooper]

Dead enemy bodies will set off the bombs, I thought they were bugged for awhile because it seemed so inconsistent.