When the sound of the first gunshots rang above his head, Singaporean Marcus Seng, 30, thought it was the sound of fireworks or a private helicopter taking off.

"I knew the sound came from somewhere above me, not at the ground level, and it was quite loud, as I could hear it clearly despite having my motorcycle helmet on," said Mr Seng, who was on his motorbike on the Las Vegas strip on Sunday night (Oct 1).

"I thought it was fireworks or something," he told The Straits Times.

He soon realised that what he had heard were gunshots. These came from the 32nd floor of Mandalay Bay Resort and Casino on his left.

After a second round of gunshots several seconds later, he saw a police car drive along the pavement in the opposite direction of the traffic, towards the hotel, and people running to get out of the concert.

"It was madness on the streets. There were gunshots every few seconds, and cars began to signal right, to move away from the hotel.

"I decided to turn right, away from the source of the gunshots. I rode away from the scene as far as possible, and away from the Las Vegas strip because touristy areas are likely to be part of a coordinated attack," said Mr Seng, a former navy officer. He had been on a solo road trip for 2½ months, and Sunday was his third day in Las Vegas.

Almost 60 people were killed and more than 500 injured when a gunman went on a shooting spree at a concert on the famous Las Vegas Strip late Sunday, raining down rapid fire from the 32nd floor of a hotel for several minutes before killing himself, in what has become the deadliest mass shooting in US history.

"I'm reeling in how close I was to the scene, but I'm more relieved than shocked and I'm glad that I'm safe," Mr Seng added. He stayed in a residential area that was not near the Las Vegas strip.

Once back in his residence, he informed friends via a Facebook post that he was safe. He added: "On a more encouraging note, I saw a team of 15 to 20 police cars responding to the scene within three minutes. Kudos to the men in uniform!"

The Ministry of Foreign Affairs (MFA) said on Monday night that there are no reports of Singaporeans injured by the shooting so far.

The ministry and the Singapore Consulate-General in San Francisco have contacted e-registered Singaporeans in Las Vegas to ascertain their safety, and the Consulate-General is in touch with the local authorities to monitor the situation closely, added MFA.