A fire broke out at a warehouse in Ubi Avenue 4 early yesterday morning, with flames engulfing two storeys of the affected unit containing party supplies.

When The Straits Times visited the scene at around 2.30am, fire engines were spotted outside the facility. Eyewitnesses, who heard explosions, told ST that the fire started around 2.10am.

The Singapore Civil Defence Force (SCDF), in a Facebook post on Tuesday morning, said it responded to a unit fire in a light industrial building at 191, Ubi Avenue 4, at about 2am.

"Upon SCDF's arrival, the fire had fully engulfed two storeys of the affected unit," it said.

"Firefighters deployed two water jets as an immediate offensive firefighting tactic to control the blaze from within the building. Two additional water jets were also deployed to protect the adjacent units."

SCDF said that firefighters faced dark and smoke-logged conditions and had to negotiate narrow stairs leading up to the mezzanine storage platform.

The fire, which involved stockpiles of party supplies such as balloons, inflatables and helium tanks on the upper levels of the unit, was extinguished within two hours.

Eleven workers from the unit had evacuated the premises prior to SCDF's arrival.

ST understands that the workers were told to gather in a common area outside the warehouse.

There were no reported injuries.

Balloon supply company Bez Balloons is believed to be operating from the warehouse unit.

The company, which does balloon decorations and printing, started in 2000, according to its Facebook page.

As at about 7.30am, damping down operations were still under way to prevent the fire from rekindling.