- The shooting will once again throw the spotlight on America's epidemic of gun violence and the ready accessibility of weapons.
- Since the 2012 massacre at the Sandy Hook Elementary School in Newtown, Connecticut, warning procedures and emergency drills have multiplied at US schools.
Police launched a manhunt on Wednesday for a shooter who opened fire at a high school in Florida, reportedly leaving between 20 and 50 people injured, officials said.
The shooting took place at Marjory Stoneman Douglas High School in Parkland, a city in the southern part of the state between Boca Raton and Fort Lauderdale.
The Margate Fire Department told CBS Miami there were between 20 and 50 victims. The extent of the injuries was unclear.
"AVOID THE AREA," the Broward County sheriff's office said on Twitter.
"There are reports of victims," the sheriff's office said. "Shooter still at large."
Television images showed students being led out of the school by heavily armed police officers and an armoured vehicle filled with a SWAT team arriving at the scene.
One injured victim was seen being placed into an ambulance on a stretcher.
Police officers in helmets, bulletproof vests and armed with automatic weapons could be seen stationed at several points around the school.
"What happened was that the fire bell rang and we all thought it was a drill because we had already had a fire drill," an unidentified student told WSVN 7 News.
"We thought it's another drill so we didn't take it seriously and then we heard pops from the other side of the school," the student said.