SINGAPORE - All lanes on the Central Expressway (CTE) towards Ayer Rajah Expressway (AYE), which were affected by an oil spill caused by a trailer, were re-opened to traffic on Wednesday evening.

Motorists were also allowed to use the Merchant Road entrance to the CTE tunnel, after road works were completed, said the Land Transport Authority (LTA) on its Twitter account at about 8.10pm.

The oil spill had resulted in a temporary closure of the Chin Swee tunnel and Merchant Road entrance on Wednesday afternoon. The tunnel, which was closed at 3.30pm, opened three hours later. A single lane along the affected stretch was re-opened at 5.55pm to facilitate peak-hour traffic flow.

A LTA spokesman said the spill was caused by a trailer which had broken down due to a mechanical fault. Officers from the Singapore Civil Defence Force and the National Environment Agency were seen cleaning up the site.

A Facebook user had posted a picture of the tunnel entrance at around 4pm, with the text: "Massive jam. CTE Tunnel closed. Stay clear."