I don't know the very latest developments on this subject, but fuel air explosives
(used by ground forces) were making a big come back recently.
It involves much less risk to attacking troops to fill a building/bunker with a
'spray' of fuel, rather than having to clear each room separately with grenades and
rifle fire.
The defenders have two choices (which they know instantly the fuel becomes
apparent). They either come out, or get incinerated (that is of course if the
attackers give them the choice
).