According to Orlando's mayor, 50 people were killed and at least 53 injured in the shooting.
A gunman went on a shooting spree at the Pulse gay club in Florida on Sunday. He was eventually shot by a SWAT team after taking people hostage.
The process of removing the victims from the club still continues, according to the Orange county sheriff.
US southeastern state of Florida, as well as the city of Orlando announce state of emergency in connection with mass shooting in the nightclub, a local police department said.
The suspect behind the shooting has been identified as 29-year-old US citizen Omar Mateen, US media reported. The CBS network added that the FBI is currently checking whether he was linked to extremists.
US President Barack Obama was informed on Sunday of the deadly shooting in the southeastern city of Orlando, and ordered the provision of federal assistance to the investigation into the incident, the White House said in a statement.