An oil spill has spurred cleaning works on the beaches of popular resort island Koh Samet in Thailand as the beaches have turned black from the oil slick.

The incident occurred on 27 July when a leaking pipeline operated by PTT Global Chemical spilled an estimated 50,000 litres of oil into the Gulf of Thailand. The oil spill has blackened beaches at Koh Samet, a popular tourism spot about 220 kilometres southeast of Thai capital Bangkok.

Tourists have been warned away from the island and those already there were evacuated as the cleaning work continued.

Thai soldiers and volunteers wearing biohazard suits struggled to clean the oil slicks from the beaches' sand while officials said that the oil spill was affecting tourism hugely, according to Reuters.

If spread to the coast of the mainland, the oil spill could affect the fishing industry as well, the officials warned.

Meanwhile, the PTT Global Chemical authorities have apologised for the spill. The company has adopted a high-pressure water spray to remove oil stains on the rocks and has reported that oil slick at Ao Prao Beach decreased noticeably on 31 July.

Scroll down to view the photos of the latest oil spill disaster that has hit the Gulf of Thailand.

Thai soldiers wearing biohazard suits take part in cleaning operations.REUTERS
Oil is seen on sand at a beach.REUTERS
Piyapong Sopakhon, a volunteer from Koh Samet, wears a plastic bag as he takes part in cleaning operations at Ao Prao Beach on Koh Samet island.REUTERS
Thai soldiers wearing biohazard suits take part in cleaning operations.REUTERS
Soldiers collect oil slick from sand.REUTERS
A cleaning vessel takes part in a clean-up operation at Ao Prao Beach Koh Samet.REUTERS
The disaster blackened beaches at the Thai holiday island of Koh Samet.REUTERS
The oil spill is having an extreme impact on tourism and could spread to the coast of the mainland and affect the fishing industry, officials and an environmental group said.REUTERS
A crab covered in oil slick is seenREUTERS
Thai soldiers wearing biohazard suits take part in cleaning operations.REUTERS