(CNN) -- A bus carrying members of a Marine Corps Reserve unit overturned at an Alabama military base Sunday, leaving 23 Marines injured, four of them critically, the military said in a news release.



A bus overturned Sunday in Alabama, injuring 23 Marines, the military said.



The passengers, members of E Company, Anti-Terrorism Battalion, 4th Marine Division, had been taking part in a training exercise at Fort Rucker, an Army post outside Ozark, Alabama.



They were departing the range at 9:20 a.m. when the accident occurred.



The unit is made up of reservists from Tallahassee, Florida, and Bessemer, Alabama. The injured were from First and Headquarters Platoons out of Bessemer, a Birmingham suburb.



By mid-afternoon, 11 of the injured had been released to their unit from the hospital.



Pictures of the wreck were provided to the news media by the military.



Ozark is about 175 miles south of Birmingham. E-mail to a friend
Where did the bus overturn? When did it happen? When did the accident happen? What has overturned? What was the bus carrying? What overturned at an Alabama military base? Who was on the bus? What is the number of Marines that have been injured? When did the accident happen according to officials? Who were injured? Who were involved?
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