WATCH: Fire in central London: More than 100 firefighters sent to tackle blaze at Mandarin Oriental hotel

Twenty fire engines and 120 firefighters and officers have been called to a fire at a a luxury hotel in Knightsbridge, central London.

Thick plumes of black smoke could be seen billowing into the sky from the luxury Mandarin Oriental hotel on Wednesday afternoon.

The fire brigade said the cause of the blaze was not yet known, but confirmed 35 calls had been made to the fire.

Witnesses tweeted that the area had been evacuated and that roads had been closed around the £600-a-room hotel.

The 12-storey Mandarin Oriental Hyde Park completed the “most extensive restoration in its 115-year history”, according to a statement published by owner Mandarin Oriental Hotel Group in May.

All 181 bedrooms and suites are “now more luxurious and comfortable than ever before” and the building’s “iconic facade was revitalised”, the company said.

The hotel is located between Hyde Park and the Knightsbridge shopping district, which includes Harrods.

It is also directly next door to One Hyde Park – one of London’s most expensive buildings – where a five-bedroom apartment was placed on the market in 2015 for £75 million.

London Ambulance has sent its hazardous area response team (HART) to the hotel, but there have been no reports of injuries at this stage. HART are specially trained medics who provide life saving medical care in hazardous environments including complex extractions and multiple casualty incidents.