Delaware Gov. Jack Markell on Thursday signed a bill decriminalizing the possession and private use of marijuana hours after the state Senate had given final approval to the legislation, USA Today reported.

Under the news law, criminal penalties will be replaced with civil fines for adults apprehended with small amounts of the drug, according to the Wilmington News Journal. Marijuana possession would be treated akin to a traffic violation, making it a misdemeanor punishable by a fine of up to $200 and imprisonment of up to five days, the Associated Press added.

However, violators under the age of 18 will still face criminal penalties for possessing marijuana, and those between 18 and 21 will do so upon their second arrest. Selling the drug is still considered a criminal offense, as is smoking it in a moving vehicle, in a park, on a sidewalk and in other public places.

Lawmakers in the lower chamber of Delaware's legislature approved the move on June 2 in a 24-14 vote; in the Senate, Republicans again voiced strong opposition to the bill introduced by Democrat Helene Keeley, USA Today noted.

"This is a vote we're going to really, really regret," GOP Sen. Colin Bonini said. "Would you want your kid smoking weed? I think the answer is overwhelmingly 'no,'" he added.

But Robert Capecchi, a lobbyist with the Marijuana Policy Project in Washington, argued in a statement that "marijuana is an objectively less harmful substance than alcohol."

"Most Americans now agree it should be treated that way," Capecchi said. "Delaware has taken an important step toward adopting a more sensible marijuana policy," the lobbyist added.

Delaware joined 19 other states and the District of Columbia, all of which have stopped charging citizens criminally for possessing small amounts of marijuana, the News Journal detailed. There was evidence that the criminal penalties had been disproportionately enforced along racial lines, an argument that turned out to be "a driving force behind this bill's passage" in the Diamond State, the newspaper added.