New Orleans police are investigating three cases in which men were robbed after arranging what they thought were dates with women they had met on social networking sites.

The most recent incident happened about 9:30 p.m. Monday in the 2100 block of Danneel Street in Central City. It ended with the 18-year-old victim allegedly being carjacked by a group of men.

The cases are leading police to advise people to use caution and common sense when agreeing to meet someone with whom they have spoken on sites such as the website tagged.com and the application Kik.

Sixth District Police Commander Bob Bardy said Tuesday that detectives are not sure all three incidents are connected but that they are not ruling out the possibility.

“The common thread is people are doing this,” Bardy said, referring to crimes that are born of meetings through social media.

The first date-turned-crime happened about 10:45 p.m. July 11 in the 1600 block of Baronne Street. Beyond the fact that the victim was robbed, details about that incident were not available.

The next one happened about 4 a.m. July 23 in the 2200 block of St. Anthony Avenue.

The victim told police he met a woman he knew only as “Ali W” on tagged.com and arranged to meet her.

They spoke in his car for about five minutes before she went inside a home on the street. She returned a few moments later with two men, who forced the victim out of his car at gunpoint and then drove away in it with the woman.

In Monday’s incident, the victim met a woman he’d been in touch with through Kik.

As in the St. Anthony incident, they spoke for a few minutes in the victim’s car until the woman got out. At that point, about nine men — four of whom were armed — forced the victim out of his car at gunpoint and took it and his wallet.

Police said the missing vehicle is a blue or purple 1998 Dodge Durango with Louisiana license plate WXX 973.

Bardy had two suggestions for anyone contemplating meeting someone contacted through a social-media site: Meet for the first time in a well-lit, populated place, and use common sense.

Follow Danny Monteverde on Twitter, @DCMonteverde.