HUNTSVILLE, Ala. — Two people were injured in an explosion Wednesday at Redstone Arsenal, where the Army develops weapons and conducts missile training, a base official said.

Deputy Public Affairs Officer Kimberly Henry said there were no fatalities and that all personnel were accounted for after the explosion at 8:45 a.m. CDT Wednesday.

She said one of the injured was being flown by medical helicopter to UAB Hospital in Birmingham and one to a Huntsville hospital. Their conditions weren’t immediately known.

There was no word on the cause of the explosion, which Henry said occurred in Building 7352, a test site that conducts missile and aviation research.

U.S. Rep. Parker Griffith of Huntsville said the explosion occurred as contract workers were removing a propellant, ammonium perchlorate, from rockets. He described the job as “highly dangerous work.”

Redstone Arsenal, which says it employs 32,000 people on 38,000 acres at Huntsville, is the center of U.S. Army missile and helicopter programs. The base also develops and maintains weapons systems for the Army.

It is also where the federal government provides explosives training for state and local bomb technicians and investigators. Planning for the National Center for Explosives Training and Research began in 2002 in the wake of the 9/11 terror attacks and the center graduated its first class last year.

The explosion appeared to be at a site separate from the center.