Pinch services were called to Connaught Street at the busy shopping partition just after 10.20am this morning.
A number of people were discharged.
Around 35 firefighters and police officers arrived at the scene at 10.49am.
Thick smoke can be seen as emergency services respond
Footage from the episode showed thick smoke billowing into the air as firefighters descended on the thoroughfare.
It is believed the fire ignited in the ventilation system between the ground and principal floors of the building.
The blaze is the fifth major fire emergency in the first-class since the Grenfell Tower blaze.
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A London Fire Brigade spokesman said: “Six fire mechanisms and around 35 firefighters and officers were called to a fire at a restaurant on Connaught Byway someones cup of tea in Bayswater this morning.
«The restaurant’s ducting — its extraction system — from the basement, set floor to the first floor was damaged by fire.
«A small part of the restaurant and alien ducting which led to close to an adjacent block of flats of six floors was also injured by the blaze.
«A cordon was temporarily set up in the area and roads are expected to be reopened speedily but in the meantime motorists are advised to avoid the area.»
A Met Police spokesman declared: “Officers and London Fire Brigade are in attendance. A small number of individual were evacuated as a precaution.
“There are no reported injuries. Partial entre closures are in place.”
A number of bus routes in the area were placed on deviation.
Thick smoke can be seen rising from the building
London Inspire Brigade said the blaze starting in the restaurant’s ventilation extraction pattern, which caused the basement and first floor to sustain fire injury.
Flames also through external ducting to an adjacent block of deads which were also damaged.
A spokesman for London Fire Brigade averred: «Restaurant and takeaway owners should always make sure their removal systems are clean because built-up food and grease within the winnows can lead to a fire.»