GREENVILLE, S.C. (AP) — A South Carolina police department is promoting safety tips for online daters after recent meetings turned into criminal cases.

The Greenville News reports that the warnings from the Greenville Police Department follow three incidents.

Police reports indicate two cases are thought to be linked to the same individuals. In each instance, a man met a woman using the mobile dating app Plenty of Fish. In each of the July 16 incidents, the men went to a designated meeting point, only to be assaulted and robbed by two to three other men.

The third case involved a man picking up another man he had just met on the dating app Grindr. Police said the victim passed out at some point and later determined that he had been raped.

No arrests have been made in the cases. All three remain under investigation, police said.

Greenville police are now reminding users of mobile dating apps to use caution whenever meeting someone for the first time. The department has posted a safety video about dating apps on its Facebook page.

Those using dating apps are urged to do their own background check on the individual to see what comes up on a web search and see if they have other social media profiles. This ensures that the person on the app is using their true identity when asking about a date.

"We don't want them to sound creepy and there are lines for dating and what's acceptable and not, but if they give you a name and you have a Facebook, Instagram or Twitter, look them up and say, 'Does this person exist anywhere else in the universe?'" Greenville police officer Michelle Lentz said.

Residents are also reminded to pick a safe, public space when meeting with the individual for the first time.

Lentz also said to make sure at least one other person knows about your date, to include where and when the date will take place.

She said it's possible that such incidents are happening more often but that victims are too embarrassed to come forward.