So far, the president has spoken to the Speaker of the House, the Senate Majority Leader, the wife of Steve Scalise, the Chief of Staff to Mr Scalise and the chief of the Capitol Police.

Alexandria police chief Mike Brown and FBI special agent Tim Slater are assuring members of the public that the city of Alexandria is safe, even as heavily-armed investigators do their work.

"This is a secure community at this point" said Slater.

Governor Terry McAuliffe, who also just spoke at the press conference, says that his "thoughts and prayers are with everyone affected by this incident".

McAuliffe adds that "93 individuals" died each day from gun violence.

The Washington Post and CBS News have been told by law enforcement officials that the gunman is James T Hodgkinson.

The Washington Post reports that Hodgkinson comes from the small community of Belleville, Illinois, near St Louis, Missouri.

Hodgkinson, 66, owns a home inspection business. When his licence expired in November 2016, it was not renewed, US media report.

He was charged in April 2006 with battery and damage to a motor vehicle. Those charges were dismissed, records show.

No confirmation from police on that name yet, however.

The White House correspondent for One America News Network tweets:

Meanwhile, a local hospital confirms it is treating two patients. Five, including the suspect, were taken to hospitals from the scene.

Image source, Getty Images

Witnesses have described the gunman as a middle-aged white man.

Republican Senator Jeff Flake, pictured, said the suspect appeared to be in his 40s "maybe 50, dark hair, white with a blue shirt on" and wearing jeans.

In a light-hearted video interview on Monday, Rep Scalise told ABC News he was never much of a baseball player - but was hoping to do well at the game scheduled for Thursday.

House Democratic Leader Nancy Pelosi says the bravery of Capitol Police "undoubtedly saved countless lives".

Eric Trump, the president's son, has been criticised by some on Twitter for a message saying there is "zero chance" mainstream news networks (MSM) would be covering the good performance of stock markets.

That led to many Twitter users questioning whether he was up to date on the news.

Shortly after, he retweeted his father's message of condolence to Mr Scalise.

Washington political reporters are now saying that there will be no House business until the afternoon - and that all members have been called to a briefing at 11:15 local time (15:15 GMT).

Republican Congressman Chuck Fleischmann was also at the baseball ground and told CNN it was a "horrible, horrible morning".

"I walked towards the home plate and heard a large 'pop'. I thought, that sounds like a gunshot. There was a pause and then a barrage of gunshots. We hit the ground. People were running, we ran and got into the dugout. Some people were hit and bleeding. It was a harrowing scene."

White House reporters are now saying President Trump has cancelled an afternoon event - the only one on his schedule for the day.

The shooting happened in the morning, Washington DC time, before the day's political business.

It is now expected that there will be no votes in the House today, and that the 10:00 debate will be cancelled.

For those who have never heard of congressmen playing baseball, The Atlantic magazine wrote a lengthy piece on the tradition in 2013, which is being widely shared.

"If you think Capitol Hill is polarized, overcompetitive, and obsessed with winning, wait until you see the Congressional Baseball Game," the sub-headline teases, external.