In a statement, Mr Scalise's office says that before he went into surgery at the MedStar Washington Hospital Center, he was in good spirits and spoke to his wife by phone.

"He is grateful for the brave actions of US Capitol Police, first responders and colleagues," it added.

House Majority Whip Steve Scalise is in a stable condition in hospital and undergoing surgery, his office has said.

CBS News reports that streets have been closed and there are restrictions around the White House perimeter.

The Secret Service said it was exercising "an abundance of caution".

The White House press pool - which covers the president for all news outlets - notes that today is Donald Trump's birthday, and no public events were listed on the schedule until a Labor Department event at 15:30 local time (19:30 GMT).

That may now change.

The US president's son Donald Jr has retweeted a remark by a political commentator who says the Scalise incident shows why Republicans were angry with "NY elites glorifying the assassination of our president"

Donald Trump Jr shared the message with the added text "this" - often used on social media to indicate strong agreement.

The message may also reference last month's controversy involving Kathy Griffin an a "beheaded Trump" prop.

Witness Noah Nathan was walking his dogs when the shooting started and said at first he thought it was a firework.

"Then I heard another one and then some people were running so I just... laid down on the ground, holding on to my dogs to make sure they wouldn't run off," he said.

"You could hear [the shots] go by, you could hear them and see them, like, flash off the road, like a little trail. And then there were a lot of people running. There was, what I understand now was the congressman (Scalise) on the outfield, he was lying down. A lot of people were just trying to get out of the way and then the police (were) returning fire."

Image source, EPA

Abandoned equipment is all that marks the scene of the shooting in Virginia.

In addition to telling the media about the shooter's movements, it's emerged that Brad Wenstrup treated the injured Mr Scalise on the playing field.

The US representative from Ohio is also a doctor, and former Army Reserve officer who served in Iraq.

Republican Representative Brad Wenstrup, who was also at the scene, has told how the gunman moved from one position to another.

He told reporters: "At the end he came out with a pistol so he must have run out of some of his ammunition on his rifle. Then the police closed down on him."

Arizona Senator Jeff Flake describes the scene of the shooting:

"Two of his [Scalise's] detail were shot... one shot in the leg, and I believe he's the one who brought the shooter down.

"He ran around for quite a while with a leg wound returning fire," he said.

Senator Flake said that Scalise was lying down for 10 minutes before other politicians could reach him to provide medical aid.

Republican Senator Rand Paul, present at the practice game, said: "We were lucky that Scalise was there because it was his security detail. We were like sitting ducks. We had no place to run."

Local police have confirmed that five people were taken to hospital - including the suspect.

Former congresswoman Gabrielle Giffords, who was shot in 2011 while in office, tweeted a message of support to all those affected.

US Capitol Police chief Matthew Verderosa has confirmed there was one gunman who was wounded. He has been taken to a medical facility.