US President Barack Obama is out of town. He is currently in California on his way to Hawaii to attend the APEC Summit.
The US Secret Service said the security of the White House was not compromised and it was not in danger.
"We received a call of shots fired near 16th Street and Constitution Avenue, which is between the White House and the Washington Monument, at about 9:30 pm" last night (8:00 am IST today), US Park Police spokesman Sgt David Schlosser told PTI.
Police are looking for bullet holes, he said, adding they have not yet confirmed that shots were actually fired.
There has been no report of any injury so far, Schlosser said, adding the suspect was last seen running across 23rd street and Roosevelt Bridge in Washington DC, several blocks away from the White House.
"A rifle was recovered" from an abandoned mid-size car which has been taken into custody, Schlosser said.
A Secret Service spokesman said the rifle was AK-47.
"Not found anybody attached to it," Schlosser said, when asked if any arrest has been made so far.