Singapore's port authority on Wednesday said that patches of oil and sheen have been sighted at a naval base on its coast after 2,500 tonnes of crude oil leaked from a damaged tanker following a collision.
However, "other than this, the oil slick has not affected Singapore's coastlines", the Maritime and Port Authority of Singapore said in a statement, adding that the water in its anchorages was reported to be clean.
The Malaysian-registered tanker MT Bunga Kelana collided on Tuesday with a bulk carrier about 13 km south-west of Singapore.
Hours after the collision, the oil slick measured four km by one km and was located about six km south of Singapore's east coast.
Cleaning efforts continued with weather, wind and tidal conditions playing an important role, the port authority said.
There were no reports of injured crew after the accident. Traffic in the Singapore Straits was not affected.