An Air Force B-2 stealth bomber crashed at Andersen Air Force Base in Guam, according to Pacific Air Forces headquartered at Hickam Air Force Base.

The crash occurred Saturday morning Guam time. Two pilots from the 509th Bomb Wing were on board and ejected, the Air Force said. They have been evaluated by medical authorities and are in good condition.

The B-2 Spirit bomber was deployed to Andersen from Whiteman Air Force Base in Missouri.

Emergency responders are on the scene, according to Pacific Air Forces.

B-2s from Andersen usually fly over Hawaii about once a month for training. On Feb. 12, the "Spirit of Kittyhawk" was parked on the tarmac at Hickam and the Air Force invited military officials and the media to inspect the boomerang-shaped aircraft.

Four of the Air Force's inventory of 21 Spirits are on a rotational deployment to Guam from Whiteman Air Force Base, where they are permanently based.

The radar-evading bombers, each of which cost more than $1.2 billion, drop 500-pound and 2,000-pound dummy concrete bombs at Pohakuloa Training Area on the Big Island in more than 20-hour roundtrips from Guam.

The Pentagon has rotated B-52 bombers and more recently, the B-2s, to Guam since 2004. Their presence is considered a deterrent to countries like North Korea, and a counterbalance to the vacuum left by large numbers of ground troops being deployed to Iraq and Afghanistan.

Geanne Ward, a resident in the northern village of Yigo, was on base visiting her husband for lunch when the aircraft crashed.

Ward said she didn't witness the crash but noticed a rising plume of thick black smoke behind the base's air control tower. She said crowds began to gather as emergency vehicles arrived on the scene of the crash at about 10:45 a.m. Saturday local time.

"Everybody was on their cell phones, and the first thing everyone wanted to know was did the pilots make it out in time," she said.

The accident occurred 11 days after a Navy plane crashed into the ocean about 20 miles northeast of Guam's Ritidian Point. Four aircrew members ejected from the EA-6B Prowler electronic warfare aircraft and were rescued by helicopter. They were treated at Naval Hospital and released.

Guam is a U.S. territory 3,700 miles southwest of Hawai'i.