Rep. Steve Scalise and Aides Shot

Washington (CNN)Rep. Steve Scalise was shot Wednesday morning in Alexandria, Virginia, a House colleague told CNN, in what sources are calling an apparent "deliberate attack."

The shooting took place at a practice for the GOP congressional baseball team.

Scalise, a member of the House Republican leadership as the majority whip, appeared to have been shot in the hip and it appeared two Capitol Hill police agents were shot, according to Rep. Mo Brooks, who told CNN he was on deck when the shooting occurred.

According to both congressional and law enforcement sources, the shooting appears to be a "deliberate attack."

Two law enforcement sources told CNN the shooter, who is in police custody, has been taken to a hospital.

Kentucky Sen. Rand Paul, who was at the practice, told CNN "it would have been a massacre" had Capitol Police not been present.

"Nobody would have survived without the Capitol Hill police," Paul said on CNN. "It would have been a massacre without them."

Arizona Sen. Jeff Flake added that he saw a member of Scalise's security detail return fire on the gunman for what felt like 10 minutes, even though the police officer was wounded in the leg.

"50 (shots) would be an understatement, I'm quite sure," Flake said when asked about the total amount of gunfire, including police returning fire.

Flake said two members of Scalise's security detail were wounded, and another man was wounded in the chest.

Once they were able, Flake said he and Rep. Brad Wenstrup, who is a physician, went out to where Scalise was lying after dragging himself away from the shooting to apply pressure to the wound. Scalise was coherent the whole time, Flake said.

The President is monitoring the situation, the White House said in a statement.
"The Vice President and I are aware of the shooting incident in Virginia and are monitoring developments closely," President Donald Trump said in a statement. "We are deeply saddened by this tragedy. Our thoughts and prayers are with the members of Congress, their staffs, Capitol Police, first responders, and all others affected."

Trump subsequently tweeted, "Rep. Steve Scalise of Louisiana, a true friend and patriot, was badly injured but will fully recover. Our thoughts and prayers are with him."

House Speaker Paul Ryan and Republican Majority Leader Kevin McCarthy are safe on Capitol Hill and receiving updates, aides tell CNN. Neither was at the practice.

Brooks said there were a number of congressmen and congressional staffers lying on the ground, and at least one of them was wounded. The Alabama Republican said he used his belt as a tourniquet to help one of the victims.

He said the shooter appeared to be a white male but added that "I saw him for a second or two." He said the shooter was behind the third base dugout and didn't say anything.

"The gun was a semiautomatic," Brooks said, adding that he was sure it was a rifle but unsure what kind. "It continued to fire at different people. You can imagine, all the people on the field scatter."

Scalise is the first member of Congress to be shot since former Arizona Rep. Gabby Giffords was shot in January 2011. Giffords was shot in the head by Jared Lee Loughner at a "Congress On Your Corner" event at a Tucson grocery store. Giffords, who authorities said was the main target of the shooting, survived the attack but six others were killed and an additional 12 were injured.

Loughner pleaded guilty in 2012 and was sentenced to life in prison without the possibility of parole.

This story is breaking and will be updated.