Rescue workers arrange a rescue operation at the construction site of the Bugis Mass Rapid Transit (MRT) Downtown Line in Singapore, July 18, 2012. A scaffolding at the construction site of the Bugis MRT Downtown Line collapsed Wednesday and killed two workers. The Chinese Embassy in Singapore confirmed that the two were from China. (Xinhua/Then Chih Wey)

Two Chinese workers were killed after temporary scaffolding at a subway tunnel construction site in Singapore collapsed on Wednesday, authorities said.

The Chinese Embassy in Singapore confirmed that the two workers killed were from China.

Eight others suffered minor injuries and were sent to a nearby hospital.

The workers were working on top of the structure at the construction site of the Bugis station railway link.

The Ministry of Manpower said preliminary investigation showed that the workers were pouring concrete, known as the casting process, into the formwork when the structure supporting the formwork collapsed.

The subway link is about three to four meters deep. The rescuers from the Singapore Civil Defense Force said the first body was found submerged in wet cement and was pressed down by wooden planks in the work area, which was 15 meters deep. Rescuers had to retrieve the bodies before the wet cement hardened.

The formwork is located between the new and old sections of a subway station and was part of the structure being built to form the underground linkway.

The Land Transport Authority said the incident happened at about 6:50 a.m.

The area affected was localized and railway station structure is substantially complete and structurally sound, it added.

The Ministry of Manpower has ordered all construction work to stop, and the Building and Construction Authority has revoked the construction permit for the site while investigations are underway.