LITTLETON, Colo. (Reuters) - Colorado gun control activists rallied on Thursday near Columbine High School, calling for an end to gun violence one day before the 19th anniversary of the massacre there and a planned nationwide student walkout.

The roughly 200 demonstrators who gathered in the Denver suburb of Littleton on a windy afternoon included a survivor of the Feb. 14 school shooting in Parkland, Florida that left 17 dead.

The walkouts and drive to sign up voters are aimed at pressuring U.S. politicians to enact tighter restrictions on gun sales in the run-up to Novembers mid-term congressional elections.

The idea is to unite and empower survivors, to stand together, said Emmy Adams, an 18-year-old senior at nearby Golden High School.

On April 20, 1999 two Columbine seniors killed 12 of their classmates and a teacher before committing suicide. Since then mass shootings have occurred with shocking frequency across the United States.

Among the speakers at the Vote for Our Lives event were Parkland High School student Carlitos Rodriguez, who told the crowd that politicians would listen if their seats were at stake.