The FBI is reviewing its tip procedure in the wake of the mass shooting at a high school in Parkland, Florida in which 17 people were killed.

The bureau had been warned last year about an anonymous online commenter going by the name “nikolas cruz” - the real name of the suspect - who wrote a comment under a YouTube video that read "I'm going to be a professional school shooter."

The bureau was unable to locate that person at the time and a bureau official told Reuters that it is reviewing how it handled the tip about the comment to see if mistakes were made.

Ben Bennight, the Mississippi bail bondsman who posted the original video, was alarmed and had contacted the FBI at the time according to a new video he posted in hours following the 14 February shooting.

"No other information was included with that comment which would indicate a time location or the true identity of the person who made the comment," sai FBI Special Agent in Charge Robert Lasky during a news conference.

The FBI’s field office in Miami where Mr Lasky is in charge did not immediately respond to a request for further comment on exactly why the commenter could not be located, the reasons for reviewing the tip procedure, and what could be changed.

Florida shooting suspect Nikolas Cruz appears in court the day after mass shooting

A white nationalist group called the Republic of Florida identified Nikolas Cruz, 19, as having ties with them the day after the shooting but the FBI believes he may have left proof of his association with the group last year on social media.

Police said Mr Cruz walked into Majory Stoneman Douglas High School around the time classes were being dismissed and opened fire with an AR-15-style assault rifle.

Florida shooting – in pictures Show all 10 1 /10 Florida shooting – in pictures Florida shooting – in pictures Police arrest a suspect in connection with the shooting at the Marjory Stoneman Douglas High School in Parkland, Florida Reuters Florida shooting – in pictures Parents wait for news after reports of a shooting at Marjory Stoneman Douglas High School in Parkland, Florida AP Florida shooting – in pictures Anxious family members wait for news of students AP Photo/Wilfredo Lee Florida shooting – in pictures Students being evacuated from the school AP Florida shooting – in pictures Students being evacuated from the school Getty Florida shooting – in pictures People gather waiting for word from students AP Florida shooting – in pictures Parents waiting for news on their children AP Florida shooting – in pictures People gather at a hotel where students were taken after the shooting Getty Florida shooting – in pictures Florida Governor Rick Scott speaks to the media as he visits Marjory Stoneman Douglas High School following the shooting AFP/Getty Florida shooting – in pictures Dr. Igor Nichiporenko, Medical Director Trauma, left, and Dr. Evan Boyer, Medical Director, Emergency Services, speak about treating victims and the suspect at a press conference outside Broward Health North hospital AP

He was a student at the school before being expelled for bad behaviour last year.

According to gun control group Everytown for Gun Safety, the shooting was the 18th in a US school in 2018.

The 17 victims included three adults and 14 children, one of the youngest among them was Alyssa Alhadeff who was just 15 years old.

All the victims' families have been informed according to Broward County police.