Oil curdling on the water appeared along the Da Nang coastline on Sunday, though its origin is still in dispute, Dan Tri reported Monday.

The oil particles are as big as the head of a chopstick, spreading over one kilometer from My Khe to T.18 beaches, both major tourist spots in the central region city, said Phan Minh Hai, deputy manager of Da Nang beaches.

Hai said he has asked the river and sea environment company at Da Nang Department of Natural Resources and Environment to clean up the oil. “It might take several days.”

Nguyen Thi Ngot, a worker of the company, said the oil particles was first spotted Saturday afternoon.

The workers said they couldn’t estimate the number of particles as they cleaned the oil together with the garbage.

But the oil has spread to a larger area, the workers said.

There were suggestions that the oil came from tar kilns in the south of Hai Van Pass, but Hai said the oil from there should have arrived first at Xuan Thieu and Thanh Khe beaches.

Some people are also concerned that the oil came from the Hoang Son South that sank off near Quang Ngai Province December 12.

Rescuers then managed to transfer 40 tons of diesel oil from the boat but there was still around 180 tons of oil that couldn’t be transferred due to strong waves.

Hai has not made any conclusion but said the oil spill has not come from any boats anchored along the city coastline.

He said the oil must have been spilled somewhere offshore many days ago and was now curdling due to a dip in temperatures.

Truong Vinh Duc, a worker of the city environment company, said the oil resulted from fishermen washing their boats offshore.

If the condition got worse, Hai said he would ask concerned agencies from the central government to help.