The so-called Islamic State (ISIS) has claimed responsibility for the deadly shooting attack on a Las Vegas music festival on Sunday night, which left 58 people dead and more than 500 injured.

The Las Vegas Metropolitan Police had identified the shooter as Stephen Paddock, a 64-year-old white American who reportedly killed himself after the incident in his nearby hotel room at the Mandalay Bay Hotel and Casino.

Stephen Paddock in a photo provided by his brother Eric Paddock. (AP)

A statement released by ISIS’s Amaq propaganda agency claims that Paddock was a “soldier of the Islamic State”.

“The Las Vegas attacker is a soldier of the Islamic State in response to calls to target coalition countries,” it said.

ISIS further claimed that the gunman had converted to Islam months ago.

Despite confirming the authenticity of the statement, Shiraz Maher, deputy director of the International Centre for the Study of Radicalisation and Political Violence (ICSR), said it was too early to confirm ISIS involvement.

“We can say the message is definitely coming from Isis, but whether Isis is just doing this as psychological warfare against the US remains to be seen,” he told The Independent.

“The more we learn about the history of the gunman, the more we will know.

“If he had converted, somebody somewhere would know. If it’s true he would have had to have some contact with Isis [and] it would strike me that this guy would have had some sort of contact, some sort of electronic signals that authorities will dig into over the coming days.”

An FBI spokesperson also said no link to ISIS had yet been found, but that investigators are still analysing Paddock’s phone and electronic devices.

“As this event unfolds we have determined to this point no connection with an international terrorist group,” he added.

“As this investigation continues we will continue to work with our partners.”

This comes just days after a 46-minute voice recording of ISIS leader Abu Bakr Al Baghdadi was circulated on the internet by his supporters.

ISIS leader Abu Bakr Al Baghdadi.

The self-proclaimed caliph of the terrorist group urged ISIS militants to “be patient and strong” against the international allied forces fighting the group in Syria and Iraq.

Baghdadi urged his supporters to “intensify strikes” everywhere, and to target “media centers” of nations fighting the organisation, according to AFP.

“The path to victory is patience and resistance against the infidels no matter how much they spread and mobilised, and regardless of the alliances they make,” said Baghdadi.