(ABC News)--Police are investigating a shooting at a park in Alexandria, Virginia, this morning, and initial law enforcement reports indicate that Rep. Steve Scalise, R-Louisiana, was among those shot.

Two officers were also shot and one suspect in custody, according to initial law enforcement reports.

The shooting took place in Alexandria's Del Ray neighborhood, where a number of members of Congress were practicing for the annual charity congressional baseball game set for tomorrow.

Witness Ben Childers told ABC News' "Good Morning America" he was in his apartment when he heard gunshots and he said he saw congressional members running off a baseball field.

"There were three members that were kind of headed over toward our apartment, so we ran down and got them into our apartment so they could shelter in place. They also said that Steve Scalise had been shot and was on the ground on the baseball field," Childs said.

Rep. Mo Brooks, R-Alabama, told CNN, "I was on deck about to hit batting practice on the third base side and I hear, 'Bam.' And I look around and behind third base ... I see a rifle. and I see a little bit of a body.

“At the same time I hear Steve Scalise over near second base scream," Brooks added. "He was shot."

Brooks said he took off his belt and he and another congressman applied a tourniquet to try to slow down the bleeding. A source told ABC News that Scalise's injury was not life-threatening.

Brooks said a security detail shot back at the active shooter. Brooks estimated that 50 to 100 shots were fired.

The Alexandria Police Department said victims were being transported to local hospitals.

The FBI has arrived at the scene of the shooting, which is about 7 miles away from the White House in Washington, D.C.

White House press secretary Sean Spicer said the president and vice president are aware of the developing situation.