ORLANDO, Fla. – Orlando police quickly dispelled a rumor Monday that there was more than one shooter involved in a nightclub massacre that left 50 people dead.

Using their Twitter account, the Orlando Police Department said "Alert: Rumors of multiple shooters are unfounded. The one shooter, Omar Mateen, is dead. #OrlandoUnited."

A post on Facebook claiming there were multiple shooters in Pulse nightclub on Sunday morning had made its way through social media.

Many were wondering if the so-called witnesses mentioned in the post were telling the truth and were worried that additional gunmen were on the loose.