Charleston Mayor Joe Riley is one of 30 mayors from around the country appearing in a new media campaign on gun law reform.

“Mayors Against Illegal Guns” has released a public service message demanding that Congress take action to prevent gun violence. The ad can be viewed at www.DemandAction.org/Mayors.

The ad is running on the Web only for now. Riley filmed his segment during his visit to the U.S. Conference of Mayors in Washington, D.C., in January, the group said.

The message is a push by supporters that Congress pass legislation requiring background checks for all sales, limit military-style assault weapons and high-capacity magazines, and make gun-trafficking a federal crime.

The group includes more than 900 mayors from 45 states and more than 1.4 million grassroots supporters, it said.