PROVIDENCE — Governor Carcieri has approved legislation that aims to strengthen the state’s social-host law by making adults liable for underage drinking anywhere on their property, not just within the confines of a house.

Carcieri yesterday signed into law the bill introduced by Rep. Jan P. Malik, D-Warren, and Sen. Walter S. Felag, D-Warren. The revised law takes effect immediately.

Previously, the law said it was illegal for someone age 21 or older to “permit the consumption of alcohol by underaged persons in his or her residence.” Because of the wording, the police had found themselves unable to hold adults accountable for teens drinking on a porch or outside the house.

The revisions correct that problem by making adults responsible for knowingly allowing underage drinking “on his or her property.”

The legislation was prompted by an incident in July 2007 when the Barrington police responded to a loud party in the backyard of a home where they found a number of youths as well as a small keg of beer, bottles of beer and other evidence of alcohol.

The incident uncovered a flaw in the social-host law. The police said they could not charge the owner of the home because the underage drinking occurred not inside the home, but rather in the yard.

The amended law also increases penalties for a number of other offenses, including underage possession of alcohol, underage transportation of alcohol in a vehicle, procuring alcohol for a minor, using a fake ID to purchase alcohol and manufacturing a fake ID.