RICHMOND, Va. — Thousands of students have walked out of schools around Virginia to participate in a national student action against gun violence.

About 300 students walked out Wednesday from Douglas Freeman High School in Henrico County, just outside Richmond. They held a 17-minute ceremony to honor the 17 students and staff members killed during last month’s school shooting in Parkland, Florida.

The students said they want Congress to pass laws aimed at preventing mass shootings, including increased background checks for gun buyers.

Freeman senior Maxwell Nardi said the walkout wasn’t something students did “for fun.” He called it “a matter of life and death, and saving lives.”

At William Fleming High School in Roanoke, about 150 students left school. Some held signs that read: “Never Forget” and “Guns Kill! Simple As That!”