President Donald Trump says suspect wrote an anti-Christian declaration and is ‘sick guy’.

United States authorities believe a gunman who is accused of trying to storm the White House Correspondents’ Association dinner was targeting US President Donald Trump and members of his administration, acting Attorney General Todd Blanche says.

Blanche said on Sunday that authorities believe the suspect travelled from California to Washington, DC, by train via Chicago.

Shots were fired on Saturday evening near the ballroom where the dinner was being held as Secret Service agents subdued the gunman and as Trump, top government officials and hundreds of journalists attended the event.

Investigators have not publicly named the suspect, but multiple US media outlets have identified him as Cole Tomas Allen, 31, of Torrance, California.

Trump told Fox News that the family of the suspect raised concerns about him to local police before the event. The president also told the TV news channel that the accused man had written an anti-Christian declaration.

“The guy is a sick guy,” he told Fox News. “When you read his manifesto, he hates Christians.”

Law enforcement officials who made initial examinations of the suspect’s electronic devices and his writings believe he intended to target Trump administration members in attendance at the dinner.

“It does appear that he did in fact set out to target folks who work in the administration, likely including the president,” Blanche told the NBC TV network.

The suspect is believed to have bought the two firearms he carried with him on Saturday night in the past couple of years, the attorney general said. He is not being cooperative with law enforcement and is expected to face multiple charges on Monday, Blanche said.

Social media posts that appear to match the suspect show he is a highly educated tutor and amateur video game developer with multiple degrees in computer science and mechanical engineering.

Video posted by Trump showed the suspect running past security barricades as Secret Service agents ran towards him. One officer in a bullet-resistant vest was shot but was recovering, officials said. The gunman was taken into custody and was not injured but was taken to hospital to be evaluated, police said.

Outside the hotel, members of the National Guard and other authorities flooded the area as helicopters circled overhead.

Trump used the incident to push his plans to construct a large ballroom next to the White House, a plan that has faced legal challenges and that polls indicate most Americans oppose.

“What happened last night is exactly the reason that our great Military, Secret Service, Law Enforcement and, for different reasons, every President for the last 150 years, have been DEMANDING that a large, safe, and secure Ballroom be built ON THE GROUNDS OF THE WHITE HOUSE,” Trump wrote on his Truth Social platform on Sunday.

The $400m ballroom has become a passion project for Trump during his second term.

Trump was unusually conciliatory after what he saw as a third attempt on his life in less than two years, calling for unity and bipartisan healing.