UPDATE: FBI takes over investigation in Fort Bliss shooting (VIDEO)

This article was updated from a previous version to include exclusive comment from Fort Bliss. 

The Federal Bureau of Investigation is examining the scene of a shooting that occurred Tuesday afternoon inside the El Paso Veterans Administration clinic near the William Beaumont Army Medical Center on Fort Bliss that left one victim and the gunman dead.

“The alleged shooter is dead and we have one casualty and that casualty is deceased. All other VA patients and staff are safe,” Maj. Gen. Stephen M. Twitty, commanding general of the base and the 1st Armored Division, said at a news conference Tuesday evening.

The victim was being treated for a gunshot wound and later died in surgery, Master Sgt. Joel Peavy told Guns.com. Several media outlets reported the victim was a VA doctor, but officials have yet to confirm that since the investigation is ongoing.

Authorities are unsure as to why the still unidentified gunman opened fire on the federal installation, but are confident the investigation will turn up details, CNN reported.

“We have hundreds of potential witnesses and we are processing those right now,” he said. “Those people were here seeking medical assistance, so we understand the difficulties that this situation presents to them,” said VA acting Director Pete Dancy.

The incident prompted a massive law enforcement response, the El Paso Times reported, with city and military police cordoning off several blocks in the surrounding area. The El Paso Police Department told Guns.com that Fort Bliss military police were handling the incident, and that city  officers were sent to help with traffic and street closures.

“We will continue to cooperate fully with military and civilian authorities at Beaumont Army Medical Center. The safety and continued care of our Veterans and the staff will be our focus throughout this situation,” read a statement from the Department of Veterans Affairs. 

The El Paso Times reported the shooting occurred at about 3:10 p.m. at the veterans facility located at 5001 N. Piedras St. The installation went into lockdown as U.S. Customs and Border Protection helicopters reportedly circled above. 

CNN reported that the VA will be closed Wednesday.

The FBI could not be reached for comment.