1. Within the radius of the blast cloud, the detonation velocity approaches that of a nuclear blast.
2. Immediately following the high pressure blast wave, a large vacuum is created which has been known to empty the contents of trenchlines and TUNNELS with extreme prejudice. The victims often are found to have lethal diaphram ruptures, along with torn eardrums and concussions.
Just in case the Taliban has a properly-constructed shelter somewhere with overpressure-resistant ventilation I suggest Lockheed gin up a few more GBU-28's.