SINGAPORE: Up to 5,000 workers were evacuated from the Hong Leong Building in Raffles Quay after they felt tremors caused by two quakes in Sumatra, Indonesia on Tuesday.

Witnesses told Channel NewsAsia that generally, they were led out of the building in an orderly manner.

Many complained of headaches and dizziness while some vomited.

Most of such complaints came from those working at the higher levels of the 44-storey building.

The building re-opened for business by 3pm, but many workers did not return to their offices.

There was talk of a crack in the building, but there has been no confirmation.

But Hong Leong Building said its technical staff had conducted checks at the Group's buildings and found that they are structurally safe.

The Building and Construction Authority (BCA) has also confirmed this.

Ong Chan Leng, BCA's Director for Special Functions Division, said: "Our professional engineers have checked, double checked and confirmed that that wasn't the case (that is, there were no cracks in the building). In any case, our buildings have a lot of inherent robustness to withstand certain amount of these forces."

Businesses operating at the building, such as the United Airlines, were disrupted after the evacuation.

Customers who had come to collect their plane tickets for flights for Wednesday morning, had found the office closed.

They told Channel NewsAsia that they had trouble getting through when they called the office.

Japan Airlines closed its office for a while, but re-opened in the afternoon. - CNA/ir