A fire that broke out in a restaurant kitchen at the Grand Hyatt Singapore hotel resulted in about 500 people being evacuated yesterday morning.

Footage of the incident shows thick plumes of smoke billowing out of the hotel in Scotts Road.

Mr Marcus Ko, a part-time events assistant who was outside neighbouring Scotts Square, said he noticed "mild" smoke at 11.15am, but it soon became thicker.

"We could smell it... People started covering their faces, and it got quite unbearable once the wind direction changed," said Mr Ko, 24.

The hotel lobby was cordoned off and firefighters arrived promptly, he added.

At least three Singapore Civil Defence Force (SCDF) vehicles and one police car were at the scene.

SCDF said it responded to the fire at 11.20am. The fire involved a kitchen stove and exhaust ducting in the Mezza9 restaurant on the second floor of the hotel.

The flames were extinguished by water sprinklers before the SCDF arrived.

Two water jets were used for damping-down operations, which refer to applying water to burnt surfaces immediately after a fire is extinguished.

This is done to prevent rekindling of the fire from hot, burnt surfaces, said SCDF.

About 500 people were evacuated from the premises by security personnel as a precautionary measure.

When contacted by The Straits Times, Grand Hyatt Singapore's hotel manager Parveen Kumar said the fire broke out in one of Mezza9's six kitchens.

There were no guests in the restaurant when the fire started as it had not opened for lunch.

SCDF gave the all-clear for guests to return to the hotel at 12.40pm, Mr Kumar added.

The hotel has resumed normal operations, although Mezza9 remains closed. It is not clear when the restaurant will resume operations.

"We extend our sincere apologies to our guests, associates and neighbours for the inconvenience caused by this incident," Mr Kumar said.

There were no reported injuries and the cause of the fire is under investigation.

Last month, equipment failure at an electrical substation caused a fire at Carlton Hotel in Bras Basah Road.

About 1,000 people were evacuated. No injuries were reported.

Electricity supply to nearby areas, including Bugis, City Hall and Marina, was also disrupted for 12 minutes.