(CNN) -- Crews worked Monday to disperse an oil slick that stretches 8 nautical miles through remote waters off the coast of northwestern Australia.
Chemicals dropped from planes over the Timor Sea have helped disperse some of the oil, but it will take weeks to clean up the spill, which comes from an oil-and-gas-rig leak that continues to discharge contaminants, the Australian Maritime Safety Authority said in a statement issued Monday.
The company that operates the oil rig said "it will be weeks before the leak can be stopped," the statement said.
The authority said it "is prepared for a protracted clean-up operation" and it has mobilized people and equipment, including aircraft, "to cope with the lengthy response."
"This leak has occurred in one of the remotest locations possible, making any operation difficult," the authority said.
The company, PTTEP Australasia, is focusing on eliminating the oil slick and stopping the well from leaking, it said in a statement that quoted its chief executive, Anon Sirisaengtaksin.
The company said it is working with authorities to "ensure that the work is done safely and with minimal environmental impact."
After the leak began Friday, 69 people were evacuated from the rig, the West Atlas.
The leak is believed to be in wells deep below the rig, the Australian Associated Press reported, quoting Jose Martins, the company's chief financial officer.