Susan Walsh / AP
People walk from the U.S. Capitol to the Washington Monument in Washington, Saturday, Jan. 26, 2013, during a march on Washington for gun control.
Residents of Newtown, Conn., the scene of a school massacre in which 20 children and six adults were killed last month, joined thousands of people gathered on the National Mall in Washington on Saturday for a march supporting gun control.
Similar organized demonstrations were planned in support of gun control in about a dozen other places across the United States, according to organizers.
In addition to the 100 people who traveled together from Newtown, organizers told The Associated Press participants from New Jersey, New York and Philadelphia would join the demonstration.
Alongside Mayor Vincent Gray, a crowd that stretched for about two blocks marched down Constitution Avenue toward the Washington Monument, where speakers called for a ban on assault weapons and high-capacity ammunition. Some of the demonstrators held signs that read "We Are Sandy Hook."
Education Secretary Arne Duncan addressed the crowd, saying he and President Barack Obama would work to enact gun control policies, the AP reported.
"This is about trying to create a climate in which our children can grow up free of fear," he said, according to the AP.
"We must act, we must act, we must act," Duncan said.
According to the AP, demonstrators held signs that read "Ban Assault Weapons Now," "Stop NRA" and "Gun Control Now." Other signs carried the names of victims of gun violence.
The silent march is organized by Molly Smith, artistic director of Washington's Arena Stage, and her partner.
"With the drum roll, the consistency of the mass murders and the shock of it, it is always something that is moving and devastating to me. And then, it's as if I move on," Smith told the AP. "And in this moment, I can't move on. I can't move on.
"I think it's because it was children, babies," she told the AP. "I was horrified by it."
The event is co-sponsored by One Million Moms for Gun Control, an independent organization that is also responsible for similar demonstrations in cities such as San Francisco, Chicago and Austin, Texas.
The Newtown massacre has reignited the debate over firearms in the United States, and last week Obama laid out a series of measures intended to curb gun violence, most significantly proposals to limit the size of ammunition magazines, ban assault weapons and require universal background checks on firearm purchases. That plan won little praise from Republicans.
Earlier this month, New York lawmakers approved the toughest gun control law in the nation, expanding the state's existing assault weapons ban and addressing gun ownership by those with mental illnesses.
Supporters of gun control held a rally in Washington D.C. calling for action following the school shooting tragedy in Newtown, Connecticut. NBC's Kristen Welker reports.