For the second time this month, a woman has come forward claiming she was sexually assaulted by the driver of an unlicensed cab she flagged down in the city.

The latest alleged attack was reported about 2 a.m. yesterday by a woman who said she was picked up by a dark mid-sized sedan while trying to hail a taxi at Linden and Pratt streets in Brighton. She said she was driven to an area near Harvard University and attacked.

Boston police went public with the report hours after Middlesex District Attorney Marian T. Ryan’s office released a sketch of the cab driver sought for the alleged Aug. 6 rape of a woman he picked up in the Seaport District.

Boston police did not immediately say if they suspect the two incidents are connected.

Yesterday’s alleged victim described her attacker as an “Indian” male in his mid-30s, about 5 feet, 8 inches, with medium build, short-cropped dark hair and “very crooked teeth.” She said he was wearing a black short-sleeved collared shirt and “had a thick accent.”

The driver from the Aug. 6 assault was described by his alleged victim as a “Hispanic or Indian/Middle Eastern male” in his late 20s to early 30s, 6 feet tall, approximately 230 to 240 pounds, with a muscular build, dark complexion, buzz-cut black hair and neatly cropped facial hair.

Authorities said the suspect in the earlier attack was driving a black Lincoln livery sedan with either a tablet or smartphone mounted on the dashboard displaying a map and fare tally. A delay of more than a week in publicly releasing information about the alleged assault prompted an outcry from Boston officials.

Anyone with information about yesterday’s assault is asked to call the Boston Police Department’s citywide Sexual Assault Unit detectives at 617-343-4400.