Chief Beck warned of inadvertently advertising your home's vacancy on social media sites like Twitter and Facebook. (Oli Scarff/Getty Images)

After touting a drop in crime at his monthly media availability, Los Angeles Police Chief Charlie Beck addressed what may be a new phenomenon - parties inside empty homes promoted on Twitter and Facebook.

"These are parties where, through social media, large groups of primarily young people are made aware of a residence that is vacant," Beck told reporters.

One in ritzy Holmby Hills near UCLA last weekend attracted hundreds of people. A Pacific Palisades teen reportedly told friends that he and his parents were going to Hawaii. A Twitter user is taking credit for bringing the masses to that house.

The chief said he had two messages for people. First, he reminded people its a felony to break into a home.

"Second of all, for those homeowners out there, if you're going to be absent from your residence, don't put it on social media."

And don't let your kids broadcast it around the world either.

As for the latest crime statistics, Beck said violent crime is down 8 percent, but he added homicides are up 9 percent in the first quarter of the year. He played down the increase.

"That's seven more homicides in a three-month period in a city that typically has 300 a year," he said. "That's not that many."

The chief said the increase was not gang related - gang crime fell 24 percent. He blamed domestic disputes, often fueled by alcohol. He expressed confidence the bump in homicides would be short-lived, given aggravated assaults are down 6 percent.

"Homicides are just an assault that has a horrible consequence," Beck said. "If assaults are down, homicides typically will trend down eventually."

The chief noted an increase in auto and home burglaries in the San Fernando Valley. Some commanders have suggested that's because the state's transferred prison inmates to county supervision.