A U.S. Republican congressman is in critical condition—and four others wounded—after being shot at a baseball field near Washington, D.C., during a practice game.

The man responsible for the attack, identified by police as James Hodgkinson, 66, from Belleville, IL, was wounded and arrested at the scene. He died after being taken to hospital, President Donald Trump later announced during a press conference.

The FBI has said that it is too early to determine if the attack was an attempted political assassination or an act of terror.

According to police, the attack occurred just after 7 a.m. Wednesday morning as Republican members of the congressional baseball team practiced on a field in Alexandria, VA.

Medics took five from the scene of a shooting at a GOP baseball practice, and a suspect is in custody, police say https://t.co/GlJczgORDi pic.twitter.com/h8lmtyEdsI

— CNN Breaking News (@cnnbrk) June 14, 2017

Rep. Steve Scalise, House Majority Whip and a Louisiana Republican, was standing at second base when gunfire erupted from behind a chain-linked fence. He was immediately struck in the hip and witnesses saw him “army crawl” toward higher grass.

A Republican staffer and a lobbyist were also shot as were two members of Scalise’s protective police detail as they exchanged gunfire with the shooter.

Police identify suspect in Alexandria, Virginia shooting as 66 y/o James T. Hodgkinson pic.twitter.com/oOb8uAvm84

— CBS46 (@cbs46) June 14, 2017

“In the field, I see Representative Scalise is shot but moving and he’s trying to drag himself through the dirt out into the outfield,” U.S. Senator and former Republican presidential candidate Rand Paul, who was also at the practice session, told media.

New video from where the gunman was taken down; he is described as a middle-aged caucasian man, some reporting he fired 50+ shots pic.twitter.com/LusOKRNA59

— CBS News (@CBSNews) June 14, 2017

“There are two staffers. They were laying down,” recounted Paul. “Then I’m seeing the shots hitting the dirt around them.

“They had to make a difficult decision: Do we lay here and stay low and hope he doesn’t hit us? Or will the shooter just advance and come closer and shoot us?”

Hodgkinson’s brother, Michael Hodgkinson, told The New York Times, that his brother was unhappy with the recent election of President Trump and had traveled to Washington in recent weeks to protest.

“I know he wasn’t happy with the way things were going, the election results and stuff,” he said.