OAKLAND -- Investigators have released video surveillance footage of a man who is accused of posing as a maintenance worker to get into a Chinatown apartment and molest a 7-year-old girl.

The footage shows the man walking to the apartment complex in the 100 block of 10th Street in Oakland and then running away after the crime, police said. The attack on the girl occurred about 3:15 p.m. last Saturday and the video was captured in the minutes before and after the sexual assault, police said.

Police said the man knocked on an apartment door and claimed to be either a plumber or a maintenance worker there to check water pipes for leaks.

The girl was home with an adult female relative at the time. Police said the woman left the girl alone in a room with the man and he began to molest her. When the girl tired to pull away, he grabbed her and held her against her will, police said. She screamed and the relative came into the room and confronted the man, who ran away, police said.

Police said the man was seen earlier Saturday at the same complex but was not let into any units.

He is described as a white man, age 50 to 55, about 6 feet tall, 160 pounds with a skinny build, a white beard and light brown hair splattered with paint. He wore blue jeans, which were also splattered with different color paint, a gray hat and a blue, white and green horizontal-striped shirt.

Police and Crime Stoppers of Oakland are offering a reward of up to $5,000 for information leading to the man's arrest. Anyone with information should call police at 510-238-3641 or the tip line at 510-637-0298.

Reach Kristin J. Bender at kbender@bayareanewsgroup.com. Follow her at Twitter.com/kjbender.