U.S. military officers say two air force pilots are safe after their B-2 Stealth Bomber crashed on the island of Guam. VOA's Kurt Achin is monitoring the situation from Seoul and has this report.

B-2 bomber during training exercise near McGuire Airforce Base, N.J., March 2001 file photo

The crash occurred Saturday morning local time as the B-2 Stealth bomber was taking off from Andersen Air Force base on Guam, a U.S. territory that lies south of Japan.

U.S. Technical Sergeant Tom Czerwinski, of the U.S. Pacific Air Force Public Affairs office in Hawaii, says no lives were lost.

"The cause of crash is unknown, pending an investigation," he said. "The pilots had ejected safely - no serious injuries. One is mobile, one is still in the hospital under observation."

A board of investigators is being assembled to evaluate the incident. U.S. officials speculate some preliminary information may be available within 30 days.

This is the first crash of a B-2, a $1.2 billion aircraft which uses highly advanced materials and technology to evade radar. It was first deployed in combat in the 1990s Balkan conflict, and later in U.S.-led actions in Afghanistan and Iraq.

The United States has 21 of the bombers, which it rotates through theaters around the world, including here in South Korea, where the United States maintains 28,000 forces to deter potential aggression from North Korea.

This is the second U.S. Air Force accident in several days. On Wednesday, a U.S. fighter pilot was killed in a collision during a combat training exercise over the Gulf of Mexico.