MECHANICVILLE — Now that spring is here, law enforcement officials are preparing for the annual rash of underage drinking parties held in parks, wooded areas and homes.

In Mechanicville, city police raided two house parties this past weekend and charged 23 people with possession of alcohol with intent to consume while under the age of 21.

Lt. William Rabbitt said one of the parties was hosted by a 15-year-old girl whose parents were not at their Madigan Avenue home.

The other party resulted in Joshua Matthews, 20, of 18 Underwood Ave., being charged with unlawfully dealing with a minor for allegedly providing alcohol to underage guests.

Rabbitt said an investigation is continuing into whether the owners of the homes knew the parties were going to be held.

“We know the parents for one of the hosts were on vacation out of the area last weekend,” Rabbit said. “We’re still trying to figure out where the other parents were.”

He said neighbors called to complain about each of the parties. The first was at about 11 p.m. Friday and the other at 1 a.m. Sunday.

“There was beer and liquor at the parties, and we’re still trying to determine where it came from. Everybody’s being pretty tight-lipped right now,” he said.

City police had recently attended a seminar on tactics for breaking up underage parties. Rabbitt said in these types of incidents the first order of business is to make sure there are enough officers on the scene.

“When we confirmed there was a party, we called in additional officers to make sure the kids don’t run away or get hurt,” he said, adding that there were no injuries at either party over the weekend.

Most of the teens are scheduled to answer the charges on Tuesday in Mechanicville City Court.

Saratoga County District Attorney James Murphy III said parents who think they’re offering a safe environment for teenagers to drink are really committing a crime.

“Collecting the keys at the door and keeping the kids in the house while they drink can lead to deadly consequences,” Murphy said. “Giving alcohol to a person under 21 who is not your child is a class A misdemeanor.”

He said anyone with knowledge of a planned underage drinking party or one in progress may call an anonymous tip line set up by the state police.

“The number is 1-866-UNDER21,” Murphy said. “We had a case in Saratoga Springs where a kid called to say she was concerned about a planned party and police parked a marked car in front of the house. The party didn’t happen.”

He said texting and cellphone conversations give teens instant contact and often a party planned for a few people can blossom to many participants.

“We’ve seen parties for five turn into parties of 50. The kids can also text each other when the party is on the move because they’ve been found out,” he said.

Judy A. Ekman, executive director of The Prevention Council, which records surveys of drinking by teenagers and data collected from parents, said 80 percent of 12th-graders surveyed said they had consumed alcohol, 55 percent of those within the previous month. For freshmen, 45 percent had drank alcohol at some point and 25 percent said they had done it within 30 days.

Only 15 percent of the parents surveyed believed that their children use alcohol on a regular basis. Sixty-four percent said they thought their kids had consumed alcohol at some point.