The rally, set for 5 to 7 p.m. Wednesday, Oct. 4, will be held outside the National Shooting Sports Foundation at 11 Mile Hill Road in Newtown.
"You will be able to sign our #LoveToLasVegas banner to send our love & support; rally against the gun industry's relentless efforts to weaken our gun laws in our nation; and demand action from the president and the 115th Congress," the Newtown Action Alliance said in a Facebook post.
Participants are invited to bring candles and signs.
"Our hearts are broken for the families of the 59 victims who have been senselessly massacred and 527 victims who have been injured. There is a long road ahead for the Las Vegas community and the families who have been directly impacted by this horrendous act of domestic terrorism. We send our love and support," the Newtown Action Alliance said on Facebook.
In December 2012, six adults and 20 first-graders were killed at Sandy Hook Elementary School.
Last year, the group also held a rally outside the National Shooting Sports Foundation, which is a firearms industry trade association, after the mass shooting at an Orlando nightclub.
"Our thoughts and prayers are with the families and loved ones of all those killed and injured in the criminal attack in Las Vegas," the National Shooting Sports Foundation said on its website.
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