A gunman wielding an assault-type rifle and a handgun took hostages and opened fire inside a crowded Florida nightclub, killing approximately 20 people and wounding 42 others before dying in a gunfight with SWAT officers, police said Sunday.

Police Chief John Mina also said the shooter had some sort of "suspicious device." He said the suspect exchanged gunfire with an officer working at the club around 2 a.m., then went back inside and took hostages, ABC News reported on Sunday.

Around 5 a.m., authorities sent in a SWAT team to rescue the hostages, and the suspect then died in a gunfight with those officers. Mina said police have not determined an exact number of casualties, but that "approximately 20" people were dead inside the club.

Source: MENA