Firefighters worked through the night to extinguish a fire that engulfed the upper floors of a commercial building in Tampines, in one of Singapore's fiercest conflagrations in recent years.

No one was injured in the blaze, which affected the fourth to sixth floors. A firefighter was taken to hospital for heat exhaustion.

The inferno started at around 1.30pm yesterday. While it was brought under control after about five hours, it had yet to be put out at press time.

Throughout the afternoon, thick, black smoke rose from CK Building in Tampines Street 92, so high it could be seen from as far away as Kallang. The cause of the fire is under investigation.

The six-storey building belongs to CK Holdings, which owns the chain of myCK department stores. Its upper floors are believed to be used as a warehouse for its goods, while the lower floors are a mix of offices and storage spaces. A total of 67 people were evacuated.

The fire took so long to put out because of the highly flammable contents in the building, said the Singapore Civil Defence Force (SCDF), which sent 110 officers and 27 emergency vehicles to the scene.

The goods included paper products and household aerosol cans, which fed the fire. Firefighters could not enter the building for around six hours.

The intensity of the fire "might have affected the structural integrity" of the building, said Assistant Commissioner Ling Young Ern, department director of SCDF operations.

This means firefighters could be at risk from falling debris, as walls and false ceilings may buckle in the intense heat and pressure.

Eventually, the firefighters went in cautiously at 7.35pm, when the fire was brought under control.

Earlier that afternoon, there were jitters among onlookers as noxious smoke caused their eyes to smart. Explosions went off, one after another, while firefighters fought the flames. The aerosol cans were combusting, and a stench of char hung in the air as ashes flew from shattered windows.

Worried-looking staff had to be ushered away from the scene, while a family member of the building's owner looked upset and was "in a daze", an onlooker told the media.

A CK employee who declined to be named said he was working on the third floor of the building when he realised there was a fire at the fourth floor warehouse.

He smelt smoke and left when the fire alarm sounded, following evacuation orders. He added that he had not thought it was serious.

People in neighbouring buildings were evacuated as well.

Mr Jason Soon, 43, marketing director of Vishay Intertechnology Asia in the building next door, recounted: "We saw white smoke at around 1.30pm or so... and came out of our building. After seeing that it got serious, we informed others to get their colleagues out."

A computer technician in his 50s, who wanted to be known only as Mr Chin, said he was evacuated from the next building at around 1.50pm. He said it was a small fire when it started, but it soon grew and "glass started breaking".

The SCDF received a call for assistance at around 1.30pm and was at the scene within eight minutes.

When officers arrived, the fire "had fully engulfed the fourth and the fifth storeys" and was spreading to the sixth storey, said AC Ling.

They could "see flames leaping out from all sides of the building".

Cleaner Liu Chang Dong, 44, who was working in a nearby building, alerted security officers when he saw the smoke. He also noticed people running out from CK Building, looking frantic.

"There were many people exiting from the stairwell when I looked out the window," he added.

In April, a petrochemical plant fire on Jurong Island raged for five hours before it was put out.

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