Eighteen young people were sent to Lafayette hospitals over the last two weeks due to a new wave of synthetic marijuana, police said.

According to the Advertiser, which first reported about the cases, nearly all of the cases involved people from Lafayette. Capt. Dwayne Prejean said most young people don't realize synthetic marijuana can at times be more dangerous than the real thing.

Prejean was reluctant to talk with the newspaper about specific cases on Monday because the narcotics unit is investigating them.

Prejean said the culprits appear to be substances known as Spice and Mind Trip. They're marketed as "legal weed," although they aren't weed and probably aren't legal, either.

Synthetic marijuana was readily available in convenience stores and head shops until a few years ago.

The Associated Press contributed to this report.