Houston, February 21: Schools across the US have received copycat threats on social media as they remain on high alert after an expelled former student fatally shot 17 people at a Florida high school, media reports said. Less than a week after the horrific incident in Parkland Florida, there have been at least 20 reports of other incidents involving a threat to a school or a weapon on a school campus nationwide.

The former student armed with a powerful assault rifle unleashed a hail of gunfire in a Florida high school, killing 17 people and injuring 15 others, including an Indian-American student, in one of the grizzliest mass shootings in modern US history. Adding to the anxiety, the spread of copycat threats on Snapchat and other social networks, where ominous messages proliferated.

There were several social media threats against Houston-area schools again yesterday. Police are taking quick action against the teenagers posting the copycat threats. And they are asking parents to do their part. Two students are facing felony charges in Fort Bend County for allegedly making terroristic threats. A 15-year-old boy was arrested at the Harmony Public School in Texas following a Snapchat he made at a gun range holding pistols and an AR-15, according to the Fort Bend County Sheriff’s Office. A 14-year-old boy was also arrested yesterday for allegedly making a threatening Snapchat post at Needville Junior High School, Texas, deputies said.

In southeastern Massachusetts, a social media post warned local high school students of a "Florida pt 2." That picture was captioned, "Round 2 of Florida tomorrow," sheriff's officials told Fox affiliate WHNS. When confronted by deputies, the student in the photo said he posted it in jest, police said.

"I'd like to ask parents out there, "When's the last time you've actually, actually walked into your kids' rooms, other than picking up their dirty laundry?" Fort Bend County Sheriff Troy Nehls asked. "Actually snooping inside their rooms, looking under their mattress to see what they're possessing? When is the last time you opened their computer screen and did a little research to see what they're looking at?"

A teenager is accused of stating on Snapchat, "You think you've seen a threat, I'll show you a threat." Students who use Snapchat and other social media to convey their emotions and messages should realise a simple post could change their lives, Nehls said.

At a senior high school in Texas, police received a tip that a student brought a gun to campus. A school resource officer arrested the student and discovered a handgun. A social media post with several angry emojis stated, "I'm gonna shoot up the school." Though most appeared to be hoaxes, administrators, police and school resources officers were on high alert Thursday and Friday, looking out for students motivated to threaten or engage in similar behaviour. Officials are not taking any chances, saying they were providing additional security at the schools.