An accident involving an oil tanker on the Pan-Island Expressway (PIE) resulted in diesel being spilled on the tarmac, causing a traffic snarl that lasted for around four hours yesterday afternoon.

The spill occurred after the Jurong Town Hall Road exit on the east-bound side, and two lanes were closed, with slow-moving traffic tailing as far back as 2km. Workers had to clean up the diesel and resurface the road.

This is the second such incident in a week - on Friday, an oil spill on the Bukit Timah Expressway (BKE) led to a massive clean-up operation and caused huge traffic jams.

The Singapore Civil Defence Force (SCDF) said it was alerted to the oil spill at around 1.40pm, and sent a fire engine to the scene.

The accident involved a tipper truck and an oil tanker. No injuries were reported, said the Singapore Police Force.

The Land Transport Authority (LTA) sent out alerts on its Twitter channel, advising motorists to seek alternative routes due to the lane closures.

The slip roads of Bukit Batok Road and Jurong Town Hall Road were also closed temporarily due to the oil spill, the LTA said.

Motorists were advised to enter the PIE farther down via Toh Guan Road.

Student Jollyn Cheong, 24, who drove past the scene at around 3pm, said: "Traffic was really slow. It took me about half an hour to clear the accident site."

Ms Cheong estimated that the spill stretched for 300m.

"All the lanes except lane 1 were closed. There were many police cars at the scene, with officers trying to redirect traffic," she said.

When The Straits Times visited the scene at around 5.30pm, traffic was inching along on the first lane, and the second and third lanes were closed for road repaving.

An LTA spokesman confirmed that one lane was reopened at 6pm and the other, at 7.05pm.

On Friday, the accident on the BKE in the morning caused oil to leak from a Malaysian-registered palm-oil tanker.

A 12-hour operation was needed to clean up the spill, which occurred just after the Mandai exit in the south-bound direction.