THE rifle-wielding gunman fatally wounded by police after shooting a Republican politician was a member of a Facebook group named “Terminate the Republican Party”.

James T Hodgkinson, 66, shot House of Representatives majority whip Steve Scalise at a congressional baseball practice just outside of Washington yesterday.

Several others were wounded in the incident.

Officers who were part of Scalise’s security detail returned fire, hitting Hodgkinson, who later died of his wounds.

Scalise, 51, the number three House Republican leader, underwent surgery at a nearby hospital, and was described afterwards as being “in critical condition”.

A law enforcement official said the shooting was being investigated as a criminal act rather than an act of terrorism.

Scalise dragged himself off the infield leaving a trail of blood as colleagues rushed to assist him.

Hodgkinson, a 66-year-old home inspector from Illinois, has had several minor run-ins with the law in recent years.

Shortly after the shooting, Bernie Sanders, the former candidate for the Democratic presidential nomination, said on the Senate floor that the shooter apparently was a volunteer for his campaign last year.

Sanders said he denounced the violence “in the strongest possible terms”.

Capitol Police officers who were in Scalise’s security detail wounded the shooter, who was then taken into custody.

He later died of his injuries, Donald Trump told the nation from the White House, in his first address as president after a shooting.

“Everyone on that field is a public servant,” Trump said. “Their sacrifice makes democracy possible.”

Scalise was first elected to the House in 2008, and is known for his love of baseball, handing out commemorative bats when he secured the job of House whip several years ago.

Texas Representative Roger Williams, who coaches the GOP team, said that one of his aides, Zack Barth, was shot, but “is doing well and is expected to make a full recovery”.

Two Capitol Police officers were also injured but were expected to recover, along with a former congressional aide who was in hospital.

Representative Jeff Duncan of South Carolina said he had just left the practice and encountered the apparent gunman in the parking lot before the shooting.

The man calmly asked which party’s lawmakers were practising and Duncan told him they were the Republicans.

The man thanked him.

That statement has taken new meaning after the discovery of Hodgkinson’s membership of a Facebook group titled “Terminate the Republican Party”.

The gunman had a rifle and “a lot of ammo”, said Senator Jeff Flake of Arizona, who was at the practice.

The House cancelled its proceedings for the day, and Speaker Paul Ryan of Wisconsin and Democratic Leader Nancy Pelosi of California both spoke on the floor issuing calls for unity.

“An attack on one of us is an attack on all of us,” Ryan said.

The shooting occurred at a popular park and baseball complex in Alexandria, where Republican lawmakers and others were gathered for a morning practice at about 7am.

They were in good spirits despite the heat and humidity as they prepared for the congressional baseball match that pits Republicans against Democrats.

The popular annual face-off, which raises money for charity, is scheduled for this evening at Nationals Park across the Potomac River in Washington, and will go forward as planned.

The team was taking batting practice when gunshots rang out and chaos erupted.

Scalise was fielding balls on second base when he was shot, according to lawmakers present, then dragged himself into the outfield to get away from the gunman.

FBI special agent in charge Tim Slater said it was “too early to say” whether it was an act of terrorism, or whether Scalise was targeted.

Ryan identified the wounded Capitol Police officers as David Bailey and Crystal Griner.

Also wounded was former congressional aide Matt Mika, who now works for Tysons Food in its Washington office.

His family said he was shot multiple times and was in critical condition and in surgery.