SINGAPORE — An oil spill caused by a dredger boat hitting a stationary cargo tanker has blackened part of Singapore's southern coastline, including the popular resort island of Sentosa, sparking concerns it may threaten marine wildlife.

As a cleanup operation continued on Sunday, spilled oil was observed along the beaches of Sentosa. The waters were closed for cleaning work, the island management authority said on Saturday.

A Netherlands-flagged dredger collided with a Singapore-flagged bunker vessel at Pasir Panjang Terminal near Sentosa on Friday, leading to the oil leakage.

Singapore's Maritime and Port Authority said in a statement late on Saturday that the oil leak from the vessel had been contained, and that the oil that escaped from the damaged tanker had been treated with dispersants.

But due to the tidal current, it said the treated oil had landed along shorelines including at Sentosa and other southern islands, a nature reserve and a public beach park. Sentosa, which attracts millions of visitors annually, houses one of Singapore's two casinos, golf courses and Southeast Asia's only Universal Studios theme park.

Part of the beachfront at the public park and at the nature reserve had been closed to facilitate cleanup efforts, the authority said. The Sentosa beach will remain open to the public but sea activities and swimming are prohibited.

The Minister for National Development Desmond Lee said agencies were working to contain the spill and clean up the affected areas. He called on the public to stay away from the contaminated beach and waterfront.

On Sunday, workers in orange suits were seen scooping up sand in a cleanup operation at an empty beach in Sentosa as black water washed up on the oil-stained shore.

Authorities deployed 18 craft for the cleanup efforts and laid nearly 1,500 meters of container booms, and temporary floating barriers to trap the spill.

Conservationists and biologists were monitoring the full extent of the damage to marine and wildlife.

A local conservation group, Marine Stewards, reportedly said there were photos of dead fish, otters and kingfishers covered in oil.

Agencies Via Xinhua