An unidentified man attacked and robbed a homeless woman late at night this week in Costa Mesa, authorities said.

The 42-year-old woman was walking along Baker Street about a block east of Fairview Road at about 3:30 a.m. Tuesday when she noticed a man walking close behind her, police said.

The man slapped the woman on the side of the head, causing her to drop a bag she was carrying, Costa Mesa police Lt. Greg Scott said.

The robber then reached into her bag and grabbed a wallet and less than $50 in cash, police said. The woman was not injured, Scott said.

The man got into the driver's seat of a gray, two-door car where someone was waiting in the passenger seat, Scott said. The two drove east on Baker Street, Scott said.

Police described the assailant as Latino, about 5-feet-9-inches tall, with a thin build and wearing a dark-colored hoodie.

— Jeremiah Dobruck

Twitter: @jeremiahdobruck