Mexican state oil company Petroleos Mexicanos said it has recovered 90 percent of the crude that was spilled into a river in the northern state of Nuevo Leon.

The incident occurred on Aug. 16 when some 4,000 barrels of crude were spilled into the San Juan River, apparently due to an illicit tap on a pipeline.

"Ninety percent of the crude has been recovered and removed" and "the clean-up work on the river banks and in the irrigation ditch dug off the main channel is continuing 24 hours a day and is expected to be concluded in eight weeks," Pemex said on its Web site.

"More than 500 people are working at the site in order to complete this work as quickly and effectively as possible," it added.

Pemex also is employing "six skimmers and 28 vacuums," which suck the oil out of the water.

"Fuel theft is a threat to people's safety and the environment," Pemex said, urging citizens to denounce any suspicious behavior related to this crime.

The theft of fuel from Pemex pipelines, known in Mexico as "milking," is common, with both individuals and gangs involved in the illegal activity.

The oil spill supposedly occurred when the illicit tap ruptured the Madero-Cadereyta pipeline in the municipality of Cadereyta Jimenez, Nuevo Leon. EFE