How to end the game in 2-player Lemmings (Super Nintendo), with no "Nuke" option?

I'm sharing my old SNES games with my kids and we were trying out the 2-player mode on Lemmings.

Sadly, it seems you can get into the situation where someone has used all of their "Bombers" and still have "Blockers" left that aren't able to be saved - leaving the 2-player game stuck with no way to keep playing without resetting the console.

In 1-player mode, there are three ways to get out of this situation:

1. Hold SELECT and Press START
2. Use the "Mushroom Cloud" button to "Nuke" all the Lemmings
3. Wait for the timer to run out.

Here is a screenshot of the second option in 1-player mode. Notice the "Mushroom Cloud" in the bottom center of the image (Next to the yellow highlighted "Digger" box):

Unfortunately, in 2-player mode the SELECT + START method doesn't seem to work - even if both players do it simultaneously. That leaves the other two options, but with no timer and no "Nuke" option on the screen, it seems that it is impossible to end the round and keep playing when you get into this situation.

Here is a screenshot showing the lack of a "mushroom cloud" button in 2-player mode:

We no longer have the game manual, but surely there should be a way to continue playing the game in those situations? Being forced to reset the console is most disappointing.

I found the answer in an internet forum, but I thought I'd post it here to better ensure the answer is preserved for posterity.

This is quoted from another source that wasn't properly cited, but I found the same text here... It seems to be from the manual for the US/NTSC version (as opposed to the PAL version where this text is missing):

You may notice that there is no Lemmings Bomb option available on the screen. If you have come to a draw or would like to restart the level, both players must move their cursors to the green and blue bars in the middle of the screen just above the Lemming icons. When this task is performed, the colored bars will turn into a Lemming Bomb icon. Both players must press their “A Button” twice simultaneously to “nuke” every Lemming on the screen and thus, end the level.

Here is a screenshot showing the "Nuclear Option" when the cursors are properly placed next to the blue and green rectangles near the lower-center of the screen:

EDIT: There is actually a second way out of this situation: It turns out it does work to have both players hold SELECT and press START at the same time. We were incorrectly executing this previously, but after talking it over with my son we tried it again and it worked. This second method does not seem to be documented in either version of the instructions.