Perhaps a bomb might be built that has a liquid oxygen tank and a liquid hydrogen tank.
The liquids might get mixed as the bomb drops.
Just after the bomb hits the ground, the mixture might seep into the ground disturbed by the MOPs. At some later time, the mixture might be set off by a conventional bomb.
The Israelis could do this themselves.
Since it would evaporate faster than it would seep, dropping down an air shaft would be necessary.
A propeller type system might be used to sink the O-H bomb deep into the pulverized rock left by the MOP.
The O-H bombs might have coordinating timers.