Two West Virginia National Guard soldiers were shot on Wednesday near the White House in Washington DC.
FBI Director Kash Patel told reporters at the scene that the two victims were in a "critical condition."
Washington DC Mayor Muriel Bowser told the press conference that the West Virginia National Guard soldiers were shot in a "targeted attack."
Police in the US capital said they had arrested one suspect.
In a speech on Wednesday night, US President Donald Trump called the shooting an "act of terror".
What do we know about the suspect in the shooting in Washington DC?
US media reports named the suspect as Rahmanullah L., a 29-year-old Afghan national who lived in Washington state.
He reportedly arrived in the US under a special visa program for vulnerable Afghans who had assisted the US during the war, after the Taliban returned to power in 2021.
An unnamed Justice Department official told the Reuters news agency the suspect had overstayed his visa and was in the US illegally at the time of the attack.
In his televised statement, Trump confirmed that the suspect had entered the US from Afghanistan in 2021.
Trump said the US would re-examine "every single alien" who entered the country from Afghanistan under former US President Joe Biden.
Shortly afterward, the US Citizenship and Immigration Services announced on X it was indefinitely stopping the processing of all immigration requests relating to Afghan nationals, effective immediately.
NBC reported that the Federal Bureau of Investigation (FBI) was probing the attack as a possible act of terrorism.
What else do we know?
The FBI's Patel said the shooting occurred at around 2:15 p.m. local time (7:15 p.m. GMT).
Emergency vehicles were seen responding to the area and at least one helicopter landed on the National Mall.
West Virginia Governor Patrick Morrisey initially said both the guardsmen had died, but later posted on X to say his office was "receiving conflicting reports" about their condition.
The shooting took place near the Farragut Metro station, less than two blocks from the White House.
From Washington, DW's Benjamin Alvarez described a "huge police presence" where authorities had cordoned off the scene and emergency vehicles' lights flashed while helicopter blades were heard overhead.
What has the US government said about the shooting?
The Pentagon has said it would send in an additional 500 troops to the US capital in response to the shooting, bringing the total in the city to more than 2,500.
"This will only stiffen our resolve to ensure that we make Washington DC safe and beautiful," US Defense Secretary Pete Hegseth said, calling the incident "a cowardly, dastardly act."
In a post on his Truth Social platform on Wednesday afternoon Trump had described the suspect as an "animal."
