Two guys lost in underground world; title?

[Larry Redfield]

Looking for a book...two guys (mine inspectors?) are trapped underground during cave-in or earthquake, and find an underground civilization. This consisted of two warring factions. The two guys are separated, and unknown to each other both become leaders of the two factions (because of their physical superiority). They try to stop the ongoing war, but are discovered and flee back to the surface, resolved to return some day and stop the conflict.
The book dates from the 60s or so. Any clue?

[scifigene]

I don't think this is your book but the description reminded me of Andre Maurois' 1930s novel Fattypuffs and Thinnifers http://en.wikipedia.org/wiki/Fattypuffs_and_Thinifers which features two boys who also end up in a warring underground civilization, rising through the ranks on opposite sides.

[Larry Redfield]

Thanx for the reply. That is not the book, but I might jump on than one anyway, it sounds interesting.

The book in question has the two guys blundering right into the midst of the war, and becoming separated while avoiding the conflict.

regards... Larry