Following the deadliest mass shooting in Orlando, which is referred as the worst terror attack in the United States since 9/11, social networking giant Facebook has switched on its safety check feature for users in the country.

The feature allows one to notify friends whether they are in the affected area and mark self and others as safe, the Verge reports.

At least 50 people, including the gunman, were killed and 53 more injured on Sunday after a mass shooting occurred at Pulse, a gay nightclub in Orlando,Florida.

The attack has been labelled as an act of domestic terrorism as well as Islamic terrorism due to the shooter pledging allegiance to Islamic State of Iraq and the Levant (ISIL).