A man died in an apparent suicide early on Sunday after crashing his car into a barricade near the US Capitol and firing shots into the air, police said.

While the man was getting out of the crashed car, it became engulfed in flames just after 4am at East Capitol Street and Second Street, US Capitol Police said.

"At this time, it does not appear the man was targeting any members of Congress, who are on recess, and it does not appear officers fired their weapons," they said.

Police said the man then fired several gunshots into the air along East Capitol Street. As police responded and approached, the man shot himself, they said. No one was else injured.

The death is being investigated by the Metropolitan Police Department in Washington, which did not immediately release the man's identity or any details of his motives.

The incident occurred amid heightened tensions and violence-filled chatter on social media following the surprise seizure of several boxes of classified government documents from former President Donald Trump's Florida resort estate. (AFP, Reuters)