(CNN) -- Singer Chris Brown and a bodyguard were arrested Sunday morning and charged with felony assault, the Washington Metropolitan Police Department said.
The arrest could have serious legal consequence for Brown, 24, since he is serving probation for the felony domestic violence conviction relating to his 2009 attack on former girlfriend Rihanna.
Brown and bodyguard Christopher Hollosy allegedly attacked a man with their fists outside the W Hotel in downtown Washington at 4:25 a.m. Sunday, police said.
The police incident report obtained by CNN identified the alleged victim as Isaac Adams Parker, 20, of Beltsville, Maryland. Parker did not immediately respond to a CNN call for comment.
Parker told police that he tried to jump into a photo that Brown was posing for with a female fan on the sidewalk when the singer said, "I'm not down with that gay s--t" and "I feel like boxing," the police report said. Parker said that Brown then punched him in the face with his closed fist, the report said.
Parker said Brown's bodyguard -- who stands 6-foot-5 and weighs 240 pounds -- stepped between them and punched Parker in the face, the report said. The bodyguard then grabbed Brown by his arm and pulled him toward his tour bus, which was parked near by, it said.
Brown and the bodyguard were taken into custody and were being held at the Second District police station, police said. Both men were later transferred to a central jail cell block for processing, police said,
Parker was treated and released at a hospital for treatment for a bruised and swollen face, police spokesman Anthony Clay told CNN.
Brown was in Washington to host a "homecoming party" at The Park at Fourteen nightclub Saturday night, according to his Twitter feed, just four blocks away from where he was arrested Sunday morning.
His representative and lawyer did not immediately respond to CNN calls for comment Sunday.
Brown is on probation in California for a felony domestic violence conviction involving Rihanna. Any arrest could be considered a violation of that probation, which could result in jail time.
Prosecutors filed probation violation charges against him twice in the past year, resulting in the judge ordering him to complete an additional 1,000 hours of community service.
Brown was arrested in February 2009 for punching Rihanna inside a rented Lamborghini on a Hollywood street. The altercation left the face of Rihanna, also a chart-topping singer, bruised and bloody on the eve of the Grammy Awards.
He entered a guilty plea seven months later and was sentenced to serve five years probation and ordered to spend more than 1,400 hours in "labor-oriented service."
His probation reports were glowing until the past year, when the district attorney's office accused him of not completing the 1,400 hours of community labor, which he was allowed to do in his home state of Virginia.
He was also accused of hit-and-run after a minor traffic crash earlier this year. The driver of the other car told investigators that Brown "went ballistic" and screamed at her after his Range Rover rear-ended her Mercedes on a Los Angeles street.
In August, Brown's lawyer reached a settlement with prosecutors to end their efforts to revoke his probation. The deal called for Brown to complete another 1,000 hours of community service.
Probation rules require Brown to stay out of all legal trouble. Even an arrest that does not lead to a conviction could result in a probation violation charge.
He is scheduled to appear before Los Angeles County Superior Court Judge James Brandlin on November 20 for a probation status hearing.
CNN's Alison Harding contributed to this report.