Police are searching for a man who went to an outreach center for LGBT people in Northwest Washington, demanded a sex act and then threatened three transgender women with a gun, according to police and the center’s director.

The incident occurred about 7:30 p.m. on Saturday outside Casa Ruby on Georgia Avenue, which runs through the neighborhoods of Shepherd Park and Takoma.

A police report says a man drove into the parking lot of Casa Ruby. The director, Ruby Corado, said an employee who was outside approached the vehicle. The police report says the driver demanded a sex act, and Corado said the employee ordered him to leave the private property and called police.

Corado said the man drove behind a restaurant across the street. There, police said, three people whom Corado identified as transgender said the same man again demanded a sex act and then displayed a weapon. Corado said the victims ran and the man drove off.

Corado said it is unusual for such an incident to occur at or near the group’s offices and added that she fears “people are looking for vulnerable” members of the population. Corado said her organization is in close touch with D.C. police and that she has discussed the case with the chief.