London, June 6: Days after Mandarin Oriental announced the completion of a multi-million-dollar renovation project, a huge blaze broke out at the luxury hotel in Knightsbridge district of London. At least 120 firefighters and 20 engines are said to be at the spot in William Street in central London. The firefighting operations are currently underway. Also Read - Fire Breaks Out at Residential Building in Delhi's Anand Vihar, 7 Fire Tenders Rushed to Spot

The fire was reported at around 16:00 hours (local time) and the cause of the fire isn’t known, a Hotel spokesperson confirmed. Thick, dark flames could be seen rising from the top of the hotel as the fire spread and tore off the roof. The fire and the operations to douse the fire brought the traffic to a standstill. Also Read - Muslim Woman on Becoming First Hijab-Wearing Judge in UK: 'Make Sure The Sound of Diversity is Heard Loud And Clear'

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“The fire alarm started and everybody was told to get outside. Everything’s fine but we don’t know how it started yet,” a person present at the spot said. Two hours later, the firefighters could still be seen fighting the flames and take it under control. On being asked if there’s anyone trapped inside the hotel, one of the police officer answered in a negative.

“We have not treated any patients but we remain at the scene as a precaution,” said the London Ambulance Service.

One of the hotel spokespersons said that the renovation work was still going on. While there are some guests staying at the hotel, the spokesperson said, no one is believed to be stuck inside.