A man was arrested after he allegedly posed as a taxi driver and then sexually assaulted a woman in his car in Patchogue early Saturday morning.

Police say the 22-year-old woman was walking near Bay Avenue and Main Street at around 4 a.m. when she was approached by the suspect, identified as Adil Raja. Raja, also 22, was driving a green Lincoln vehicle and identified himself as a taxi driver. He offered a ride and she accepted, asking him to take her to an area near a store in Patchogue.

Police say Raja instead took the woman to a different location in Patchogue, displayed a BB gun and then sexually assaulted her in the back of the vehicle.

Following the incident, the woman got out of the vehicle and Raja drove away, police say. The victim called 911, and a description of Raja's vehicle was broadcast over police radio. He was eventually spotted by police on the Sunrise Highway service road in Patchogue, and was pulled over and arrested .

Raja, of Central Islip, is being charged with first-degree rape.

Detectives are asking anyone who may have been a victim to a similar incident to call the Fifth Squad at 631-854-8552.