BEIJING - ConocoPhillips China, a subsidiary of the US-based oil company ConocoPhillips, said on Friday that oil and mud leaking from two of the company's platforms in the Penglai 19-3 oilfield in China's Bohai Bay have totaled 2,500 barrels so far, as more pollutants have been found during the company's clean-up efforts.

The company's announcement came after Chinese maritime authorities urged it to apologize to the public for its poor handling of the oil leaks.

The Penglai 19-3 oilfield is China's largest offshore oilfield, with daily production of about 160,000 barrels. ConocoPhillips holds a 49-percent stake in the field, while its Chinese partner, the China National Offshore Oil Corporation (CNOOC) has 51 percent.

The State Oceanic Administration (SOA) asked ConocoPhillips last weekend to explain why it failed to clean up the mess in a timely fashion and urged it to make an apology.

The company missed a deadline for recovering oil-contaminated mud on Sunday, which was partly due to technical problems and typhoons, the company said.

The company said that as of Thursday, 70 percent of the contaminated mud has been recovered, with the clean-up efforts scheduled to be completed by the end of this month.

The oilfield's C-20 oil well, which is located near the company's Platform C, was permanently deactivated on June 19.

The amount of oil rising to the surface of the bay has been reduced to one to two liters daily since July 20, and a specially-designed containment device has been installed near the company's platform B to capture the oil, the company said.

The oil giant said it has recovered 1,700 barrels of oil-contaminated mud, as well as 440 barrels of oil from the surface.

The company has deployed 900 employees and 33 vessels to clean up the leak.

"We will cooperate closely with CNOOC to minimize the impact of the oil leak on the environment and try our best to finish the clean-up work by the end of August," the company said.

The company first reported the two oil spills in the Penglai 19-3 oilfield to authorities in June. The oil spills have been seen spreading to beaches in the northern Hebei province and northeastern Liaoning province. The spills have been blamed for losses in the provinces' tourism and aquatic farming industries.