Of the eight people involved in Friday morning's Kranji Expressway accident, six suffered minor scratches and have been discharged from the National University Hospital (NUH). Two people are still being treated. The are in "stable condition", NUH said.

Seven workers from battery company Energizer are among those involved in the accident. It is unclear where the eighth worker is from.

The workers were injured when the bus ferrying them crashed into another private bus, causing a three-hour jam on the expressway. Witnesses say the jam started before 6am, and traffic is still not back to normal at 9.30am. Preliminary checks with the Traffic Police and Land Transport Authority reveal that the entire expressway was closed between 6am and 8am.

The workers had been picked up and were on their way to work at the company's factory in Tuas said Energizer industrial relations manager Mr Kelvin Hor who was notified of the accident at 6.55am Friday morning.