As Vice President Joe Biden convenes a meeting of anti-gun groups today, some of them appear to be ginning up an ad campaign to demand greater regulation of firearms following last month's mass shooting of schoolchildren in Newtown, Conn.

• Mayors Against Illegal Guns Action Fund, the group backed by New York CIty Mayor Michael Bloomberg and Boston Mayor Thomas M. Menino, is on the air with ads in Colorado and Wisconsin, Federal Election Commission filings captured by Political Ad Sleuth show.  The mayors' group also has run advertising in Washington — presumably aimed at members of Congress — as well as other locations where mass shootings have occurred. 
• Meanwhile, Brady Campaign to Prevent Gun Violence recently released new public service announcements featuring celebrities such as Mandy Potemkin, Mark Ruffalo, and Rosanne Cash  on the web. However a version of the ad, captured by Sunlight's Ad Hawk and shown above clocks at a made-for-TV 30 seconds. Sunlight has contacted the Brady Campaign about its plans but has not heard back by the time of this posting.

The  new 30-second ad from Mayors Against Illegal Guns features Roxanna Green, mother of nine-year-old Christina-Taylor Green, who was killed along with five others in the shooting in Tucson, Ariz. two years ago where former Rep. Gabrielle Giffords, D-Ariz., was injured. It refers viewers to the group's website, DemandAPlan.org which urges lawmakers to strengthen criminal background check laws, ban assault weapons and high-capacity ammunition magazines, and to make gun trafficking a federal crime. 

The group said it would air the ad in Tucson at 10 a.m. on the anniversary of the shootings, which was yesterday; however, because Tucson doesn't fall in one of the top 50 media markets in the country, stations there are exempted from reporting ad buys to the FCC.

MORE: Sunlight's coverage of the gun debate.

The FCC records show ads airing in Denver; however, the amounts reported are not large: just $1,075 for ads on the ABC affiliate. The state legislature, due back in session today, is going to be considering numerous gun-related bills following the shooting in an Aurora, Colorado movie theatre last summer. A pro-gun rally is planned outside the Capitol building this afternoon. 

Reported ad buys in Wisconsin, where a mass shooting took place in a Sikh temple last summer, amounted to just $325. A query to Mayors Against Illegal Guns about the size of the ad buys was not returned by the time of this post. The nonprofit group spent $175,592 on issue ads during the 2012 election cycle.

So far, Sunlight's trackers have not picked up any ads from pro-gun groups, but the amounts spent so far by the anti-gun lobby pales by comparision to the millions that the leading gun-rights lobby, the National Rifle Association, has spent on campaign donations and lobbying in the last three decades.