The eruption has been going for weeks. So far it hasn't been catastrophic, but it has been creating new ground.
The men are described as senior Afghan army officers who were vetted before being allowed to participate in training exercises. They are not considered a threat, officials say.
Can you catch it from sweat on a cab seat? Will blood transfusions help? Who really wants to go to Africa and pitch in? Is it too late? A leading virologist answers burning questions about Ebola.
More than 5,500 firefighters are battling the so-called King Fire in the Sierra Nevada forest area. Some 2,800 people have been evacuated.