Are Student Walkouts Protected By the First Amendment?

After the mass shooting at Marjory Stoneman Douglas High School in Parkland, Florida, students around the country quickly began to protest gun violence. One way gaining much attention: student walkouts. School administrators have responded both positively and negatively to these demonstrations. Now various advocacy groups are calling for  a national walkout for 17 minutes at 10 a.m. March 14 in solidarity with the victims of the Florida tragedy. Are these protests protected by the First Amendment?