(AFP) -- "The executor of the Las Vegas attack is a soldier of the [Isis] and he carried out the operation as a response" to calls to target countries fighting the [terrorists], [Isis] propaganda outlet Amaq said on the Telegram online messaging service.

It dubbed 64-year-old Stephen Paddock, who shot dead at least 58 people from a high-rise hotel window on the Las Vegas Strip, a "soldier of the caliphate" with the nom de guerre Abu Abdel Bar al-Amriki.

"The author of the Las Vegas attack converted to Islam a few months ago," Amaq said in a series of messages.

"From a hotel overlooking a music concert, [Paddock] opened fire on one of the groups, leaving 600 dead or injured, until using up his ammunition and becoming a martyr."

The group provided no evidence to back up its claims, and US security officials remained cautious amid no other signs to connect Paddock to [Isis].

Early in their investigation police said they had no information to link him with international terror groups.

In response to a query, Central Intelligence Agency spokesman Jonathan Liu said they were aware of Isis claim.

"We advise caution on jumping to conclusions before the facts are in," Liu said.