Las Vegas shooter Stephen Paddock used "incendiary" bullets to fire at a fuel tank near the concert where he kill scores of people, investigators believe after finding incendiary rounds in Paddock's room and near a fuel tank.

Paddock shot the incendiary bullets, which are designed to ignite once they land, at a 43,000-barrel fuel tank by McCarran International Airport, leading investigators to believe he tried to cause an explosion with the rounds, unnamed law enforcement officials told CNN.

It was previously reported that officials were aware Paddock had fired at the tank during the attack, but not until now was it known that incendiary rounds were likely used.

Paddock's room also had tracer rounds, rounds that produce a flame when fired to assist shooters to aim more accurately. However, nothing has been uncovered yet to suggest they were used during the attack.

Bulletproof vests and a breathing apparatus were also recovered from Paddock's room.

Paddock opened fire from the 32nd floor of the Mandalay Bay hotel on concertgoers at the Route 91 Harvest country music festival on the night of Oct. 1.

Paddock was found dead in his hotel room by law enforcement after the shooting.