A mass shooting at an Orlando gay nightclub on Sunday which left at least 50 people dead is the worst gun atrocity in US history.

Dozens of people were left injured after a gunman opened fire at approximately 2am at Pulse, a gay dance club in Florida state.

While the motive of the attack remains unclear, it quickly became the deadliest shooting of its kind in the country.

Deadliest mass shootings in US history

On 16 April 2007, 23-year-old Virginia Tech student Seung-Hui Cho shot 32 people to death on the Blacksburg, Virginia, campus before killing himself.

The dead included 27 students and five faculty members.

On 14 December 2012, 20-year-old Adam Lanza killed 28 people, including himself, his mother, 20 primary school children as well as six staff members at Sandy Hook Elementary School in Newtown, Connecticut.

Lanza suffered from extreme mental health issues that weren't treated, a report found.

On 16 October 1991, 35-year-old George Hennard crashed his truck into a packed restaurant in Killeen, Texas.

There he shot and killed 23 people, wounding 27, before turning the gun on himself Twenty-seven others were wounded.

The Texas massacre is the deadliest shooting to not happen at a school in US history.

On 19 July 1984, James Huberty, a 41-year-old former security guard who had lost his job, opened fire at a McDonald's in San Ysidro, California.

He managed to kill 21 employees and customers, including children, before being shot dead himself by a police sniper.

On 1 August 1966, former US Marine Charles Joseph Whitman, 25, killed his mother and wife, then went on top of a tower at University of Texas at Austin and killed 16 others.

He also wounded at least 30.

On 2 December 2015, Syed Rizwan Farook, 28, and his wife Tashfeen Malik, 27, killed 14 people and injured 21 others in an attack on an office Christmas party in San Bernardino, California.

It is believed the couple were inspired by Islamic extremism.