Make a save after you turn the glowing sphere in this area, just in case you need a redo.
Once you see the mummies emerging turn and run
. When you get to the three-way split in the path, take the right side, luring the mummies to you and away from the exit. Make the complete loop around (not back through the middle) and your path to the exit should be clear. As you get close to it it will block your exit and you'll get caught, which at this point is ok.