FAIRBANKS -- Fort Greely has declared five so-called “shelter in place” alerts over the past two weeks, apparently in response to recent North Korean missile test launches.

The alerts announced over loudspeakers advise people on the fort to stay indoors and take precautions to protect themselves from the toxic exhaust of interceptor missiles that would be launched from Greely in an attempt to knock down U.S.-bound enemy ICBMs. And the announcements have rattled some who live on post.

Steve McCombs was out hiking last week about three miles west of Fort Greely’s missile-defense base, headed toward a couple of ponds he likes to fish in, when he heard a siren followed by an announcement blared-out over the post’s loudspeaker system.

“I was walking in there and then started to hear these announcements and then started to kind of get a little bit startled,” he said in an interview Wednesday.

McCombs is a retired schoolteacher and state forestry dispatcher who lives in nearby Delta Junction. And he, like most people who live around Greely, has for years heard announcements over the post’s loud PA system that’s called the Giant Voice. But he says the announcement he heard July 30 calling people on post to take shelter was pretty unsettling.

“I figured there may have been something that happened with the North Koreans again,” he said.

McCombs was referring to common knowledge among the locals that Fort Greely’s security level is elevated whenever North Korea launches missiles. Post spokesman Chris Maestas declined to confirm that and deferred to the Missile Defense Agency, which didn’t respond to queries.

Maestas says announcements went out five times over the past two weeks, twice each on July 24 and 30 and again on Tuesday. Each was preceded by North Korean missile launches that weren’t part of an attack but rather apparently for a display of saber-rattling.

“The announcement is a shelter-in-place notification,” he said, explaining that the alerts direct workers and residents to “go indoors, close windows or doors. If you’re in a vehicle, go ahead and roll up your windows. Turn off any intake fans or high-ventilation intake systems.”

Maestas says the precautions are intended to minimize the chances of human exposure to the toxic exhaust that’s blasted out of an interceptor’s solid-fuel booster upon launch. That’s not a problem when the interceptors take off from remote launch facilities, like one at Vandenberg Air Force Base in California, where two interceptors were launched during a March 25 test.

But Fort Greely’s missile base is located about a half-mile from its residential area. And a pamphlet provided by post officials says it may also be necessary to tape plastic over vents, windows, doors and electrical outlets and switches. Maestas later said post officials haven’t ever given that guidance to post workers or residents.

Another pamphlet provided to post personnel advises residents that it may be necessary to hole up in a shelter-in-place room, like a bathroom, and close the door.

That’s where one person who lives on post took shelter during the July 30 alerts. She asked not to be identified but says the whole ordeal was scary, especially because it went on so long. McCombs, the hiker, noticed the same thing.

“I would say that it went on for at least a half-hour,” he said.

McCombs says as he was listening he wondered whether he too should try to find shelter — then realized he was way out on the trail, an hour away from his vehicle.

“Going out for a quiet day in the woods and then you hear all this chatter that’s coming over the air … I started thinking, ‘Was this a drill?’ And as it went on I thought maybe something happened.”

Maestas, the post spokesman, says Greely’s behavioral-health workers haven’t seen an uptick in requests for counseling to relieve anxiety caused by the announcements. He suspects that’s mainly because those who live and work on post know that they’ve signed up for.

“I think when you take a job here, being assigned to Fort Greely, whether you’re a soldier, civilian, family or tenant, you really understand the importance of the mission being conducted here,” he said. “It’s all about ballistic-missile defense of the United States.”

According to Maestas, the length of the five recent shelter-in-place alerts lasted from 5 to 25 minutes each.