U.S. Rep. Mark Kirk and police on Monday warned about a highly potent form of marijuana they say is showing up more in the suburbs.

Kirk also unveiled proposed legislation that would create tougher criminal penalties for anyone convicted of selling highly potent marijuana.

The drug variety in question, known on the street as Kush, is far more intoxicating than what was typically in circulation a decade ago, according to a news release from Kirk's office.

Named after a region in the Middle East, Kush has been around for years. Officials said it's become more plentiful here recently because local drug dealers have discovered it can be more profitable than other types of marijuana.

Criminal penalties for dealing the drug also are lighter than those for cocaine, said Kirk, a Highland Park Republican.

"Dealers told (police) they were going into Kush because of the light sentences," Kirk said.

Kirk talked about the drug and his legislative remedy at a news conference in Chicago and in an interview afterward. He was accompanied by Waukegan police Chief Artis Yancey and representatives from the Lake County sheriff's office and Lake County Metropolitan Enforcement Group.

Kush has an unusually high percentage of tetrahydrocannabinol, or THC, the main psychoactive substance in marijuana, Kirk said.

Drug producers have been able to make marijuana stronger through growing techniques that allow them to control light, temperature and other factors, according to the news release.

Kirk backs legislation that would enhance federal drug-trafficking penalties to deal with this variety.

Kirk's plan would target people distributing marijuana with a THC content of 15 percent or more. The Kush variety, authorities said, has a THC content of at least 20 percent.

The law, if passed, would not apply to people convicted merely of possession.

The proposed legislation would increase maximum fines to $1 million for an individual or $5 million for a group and would boost maximum prison sentences to 25 years.

Penalties would increase for second offenses.