A teenage student at the Marjory Stoneman Douglas High School in Parkland, Florida, where 17 people were killed and a dozen others injured after a gunman stormed the school with an AR-17 rifle, has hit out at Donald Trump Jr., calling him “immature.”

Ever since the tragedy struck the Parkland school, David Hogg had been vocal about it and even urged lawmakers and politicians to implement gun control measures.

Hogg’s criticism came after Trump Jr. liked two tweets that claimed the former was a “plant,” who was being coached and scripted because his father was a retired FBI agent.

Trump Jr. liked a tweet by TV show host Graham Ledger that was linked to a story by the far-right pro-Trump website, Gateway Pundit. The story suggested Hogg’s father taught his son to publicize "anti-Trump rhetoric and anti-gun legislation."

Speaking of Trump Jr.’s actions, Hogg said: “I think it’s a testament to the sick immaturity and broken state of our government when these people feel the need to peddle conspiracies about people that were in a school shooting where 17 people died and it just makes me sick. It's immature, rude, and inhuman for these people to destroy the people trying to prevent the death of the future of America because they won't,” Buzzfeed News reported.

Trump Jr. also liked another tweet by True Pandit, a Philadelphia-based conservative news organization that made fun of Hogg, calling him “the kid who has been running his mouth about how President Donald Trump and the GOP are teaming to help murder high school kids by upholding the Second Amendment.”

Hogg also commented on the president's tweet blaming the FBI for the mass shooting at the Parkland school.

“Very sad that the FBI missed all of the many signals sent out by the Florida school shooter. This is not acceptable. They are spending too much time trying to prove Russian collusion with the Trump campaign - there is no collusion. Get back to the basics and make us all proud!” Trump tweeted on Feb 17.

Referring to the president’s tweet as “disgusting,” Hogg said: “The FBI are some of the hardest-working individuals I've ever seen in my life.”

During an interview with NBC News, Hogg urged Trump to take action against gun violence.

“You're the president. You're supposed to bring this nation together, not divide us. How dare you? Children are dying, and their blood is on your hands because of that. Please take action. Stop going on vacation in Mar-a-Lago. Take action. Work with Congress. Your party controls both the House and Senate. Take action, get some bills passed, and for God's sake, let's save some lives,” Hogg said.

The Parkland school shooting incident unfolded Feb. 14 when armed teenager Nikolas Cruz entered the school campus and randomly fired at students and teachers. Cruz, who was a former student of the school, was arrested and charged with 17 counts of premeditated murder.