(CNN) -- China on Thursday continued its nearly weeklong effort to clean up an oil spill that has dumped 1,500 tons of crude into the waters in a northeastern province.
Officials are scrambling to prevent the oil in Liaoning province from spreading out into the Yellow Sea and international waters.
About 800 boats equipped with oil absorbers and dispersants have been dispatched. And crews are dumping 30 tons of oil-eating bacteria daily.
Ship traffic at Dalian, China's second-largest port for crude oil imports, was limited to not interfere with the cleanup efforts.
About 420 vessels were turned away in the past four days, the state-run news agency Xinhua reported.
Fishing, a major industry in the area, has been banned until the end of the summer.
While Beijing is optimistic that the cleanup will be complete by Friday, analysts argue it may take months to contain the oil's spread.
The surface area of the spill covers 166 square miles -- a fraction of the size of the BP spill in the Gulf of Mexico, which is estimated at about 2,700 square miles .
The spill began after two pipelines exploded Friday in northeastern province of Liaoning. No deaths or injures have been reported.
CNN's Emily Chang contributed to this report.