At least 16 people were arrested during a peace vigil outside the National Rifle Association (NRA) on Tuesday, as activists staged a "die-in" to demand gun reform in the wake of the mass shooting in Orlando earlier this month.

The demonstration, organized by the peace group CODEPINK, began Monday night and lasted into Tuesday morning as activists blocked the entrance to the NRA's headquarters in Fairfax, Virginia and lay down on the ground to symbolize victims of gun violence. The action was tracked on Twitter with the hashtag #DisarmHate.

Protesters held banners reading "Ban Assault Weapons" and "Stop Killing Our Kids" and wrote the names of the Orlando victims on paper hearts that they strung up on trees around the NRA's building. The group targeted the gun organization to protest the association's "relentless lobbying for putting military weapons in civilian hands."

"Committing ourselves to no longer letting the NRA hold our country hostage!" CODEPINK wrote on Twitter.

The protest comes just a day after the U.S. Senate failed to pass four gun reform measures, including legislation that would have strengthened background checks and prevented suspected terrorists from purchasing firearms. Activists said even those amendments did not go far enough, as the shooter in Orlando's massacre, Omar Mateen, would still have obtained his weapon legally under those restrictions.

Also participating in the protest were members of Muslim groups, LGBTQ organizations, and others who have been affected by gun violence.

Reading the names of people killed in Orlando outside of the @NRA at the peace vigil :( pic.twitter.com/YCknH13sgf

— CODEPINK (@codepink) June 21, 2016

Morning vigil - committing ourselves to no longer letting the @NRA hold our country hostage! #disarmhate pic.twitter.com/i0e01R1k3N

— CODEPINK (@codepink) June 21, 2016