Islamic State group claim Las Vegas mass shooting as Trump addresses the nation

A gunman who shot dead at least 50 people at a pop concert in Las Vegas was a member of the Islamic State group, media linked to the militants has claimed.

IS' Amaq news agency claimed that 64-year-old Stephen Craig Paddock had converted to Islam prior to carrying out the attack which was done on behalf of the group.

"The person who carried out the Las Vegas attack was a soldier of the Islamic State and the attack was in response to calls to target the countries of the coalition," read one Amaq tweet, referring to the US-led anti-IS military alliance.

"[The shooter] had reverted to Islam a few months ago," read another tweet.

Paddock opened fire on a crowd watching a pop concert with an automatic weapon from his hotel room, killing at least 50 people and injured hundreds more.

Police believe Paddock committed suicide before a SWAT team stormed his hotel room.

There is no confirmation from US officials if Paddock was connected to the group, while IS offered no proof to back up their claims.

IS have claimed responsibility for a number of massacres in Europe and the US without providing evidence of a direct link between the attackers and the group.

Many of them are thought to have been carried out by groups or individuals sympathetic to IS but not under direct orders from the group.

President Donald Trump made a sobering televised speech to the nation hours later, calling for calm. He described the shootings as an "act of pure evil".

"We are joined together in sadness, shock and grief," he told Americans.

Trump will visit Las Vegas on Wednesday to pay his respects, the president added. He did not mention IS in the speech, with the claim coming shortly before his address.

In an earlier tweet, Trump offered his condolences to the families of those affected.

"Warmest condolences and sympathies to the victims and families of the terrible Las Vegas shooting. God bless you!"