Over 18 guns, explosives found at house of Las Vegas gunman who killed 59

Authorities have said they had recovered a weapons cache including firearms, explosives, and ammunition from a house owned by Las Vegas gunman Stephen Paddock, as they upped the death toll from the attack to 59.

Sheriff Joseph Lombardo said officers searching the house in Mesquite, Nevada recovered "in excess of 18 additional firearms, some explosives and several thousand rounds of ammo, along with some electronic devices we're evaluating at this point."

Lombardo said the death toll from the Sunday night assault on an open-air concert on the Vegas Strip had risen to 59, while 527 people had been injured.

He said law enforcement were working four separate crime scenes: Paddock's room at the Mandalay Bay hotel, the concert venue, the gunman's house in Mesquite, and another house he owns in northern Nevada which a SWAT team was poised to raid.

The arsenal uncovered in Mesquite comes on top of at least 16 firearms discovered in the Vegas hotel room, from which Paddock launched the deadly assault before killing himself.

Lombardo said investigators had discovered several pounds of an explosive called tannerite in the Mesquite home, as well as ammonia nitrate, a type of fertiliser, in the gunman's car.

Asked if they had discovered anything to bolster the claim of responsibility by the Islamic State group, Lombardo replied: "Good for them -- no, we have no evidence of that."