PORTLAND — Maine’s largest city legalized possession of marijuana for recreational use on Tuesday in a vote that has been eyed as an indicator of support levels in the Northeast following last year’s votes out West.

The proposal, making it legal for adults 21 and older to possess up to 2½ ounces of pot in the city, received about 67 percent of the vote in unofficial citywide results. Buying or selling marijuana, or using it in public places, would remain illegal.

The vote in Maine, where medical marijuana has been legal since 1999, came a year after Washington and Colorado voters passed statewide referendums legalizing possession of up to an ounce of pot by adults 21 and over.

“Portland is just one domino in a series of dominoes that have been falling,” said David Boyer, Maine political director for the Washington, D.C.-based Marijuana Policy Project. “With the overwhelming support that we got, you can definitely tell it’s a mandate over here in Portland, that our current policies aren’t working for marijuana and that they want change.”

The group, which provided financing and organizational support for the Portland measure, says Maine is one of 10 states it has identified where it intends to support statewide legalization efforts in the next few years.

The vote was largely symbolic because it won’t override state and federal laws that make it illegal to possess marijuana. Under Maine law, possessing 2½ ounces or less of marijuana is already a civil offense, where violators are issued a ticket and fined.

Critics say marijuana use carries with it a number of health risks and that legalizing it sends a bad message to young people. But supporters say that marijuana is less harmful than alcohol and that a majority of Americans now support legalizing the recreational use of pot.

“This is truly a victory for science, for common sense and for liberty,” Democratic Rep. Diane Russell of Portland said in a statement.

Boyer said that they intend to push legislation that would allow marijuana to be taxed and regulated, like alcohol. If the legislative route fails, they will seek to put it on the November 2016 ballot, he said.