PARKLAND: At least 17 students were killed and a dozen others injured after a student of a high school in Florida opened fire.
The 19-year-old former student with a gun had once been expelled for disciplinary problems from the school.
Authorities said the attacker was arrested after the incident.
The violence erupted shortly before dismissal at Marjory Stoneman Douglas High School in Parkland, a placid, middle-class community about 70km north of Miami.
Television footage showed images of bewildered students streaming out of the building with hands raised in the air, as dozens of police and emergency services personnel swarmed the area.
Florida’s two US senators said the assailant wore a gas mask as he stalked into the school carrying a rifle, ammunition cartridges and smoke grenades, then pulled a fire alarm, prompting students and staff to pour from their classrooms into hallways. There he opened fire on the students and staff, Senator Bill Nelson said.
The attacker was identified as Nikolas Cruz, who previously attended the high school and was expelled for disciplinary reasons, Broward County Sheriff Scott Israel said at a news briefing hours later.